Haptic operating device with a rotating element and method

ABSTRACT

Apparatus and method for operating vehicles by way of a haptic operating device having a rotating unit. Selectable menu items are displayed on a display unit, and a menu item being selected by rotating the rotating unit. The rotating unit latches at a number of haptically perceptible latching points during rotation. The number and rotational position of the haptically perceptible latching points is dynamically changed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of copending U.S. patentapplication Ser. No. 14/747,025, filed Jun. 23, 2015; which was acontinuation-in-part of U.S. patent application Ser. No. 13/823,781,filed Mar. 15, 2013, now U.S. Pat. No. 9,091,309 B2, issued Jun. 28,2015; which was a §371 national stage of international patentapplication PCT/EP2011/004623, filed Sep. 15, 2011; this applicationfurther claims the priority of German patent applications DE 10 2010 045436, filed Sep. 15, 2010, DE 10 2010 055 833, filed Dec. 23, 2010, andDE 10 2015 110 633.7, filed Jul. 1, 2015; the prior applications areherewith incorporated herein in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a haptic operating device having amagnetorheological transmission apparatus and, in particular, amagnetorheological force or torque transmission apparatus, thetransmission between a first component and at least one second componentwhich is stationary or moves relative to the first component being ableto be changed by the magnetorheological properties of a fluid betweenthe components. The haptic operating device according to the inventioncan be used in various technical fields, for example for operatingtechnical equipment such as vehicles or industrial installations or foroperating washing machines, kitchen appliances, radios, hi-fi systems orother devices.

Magnetorheological fluids have very fine ferromagnetic particles, forexample carbonyl iron powder, distributed in an oil, for example.Spherical particles having a production-related diameter of 1 to 10micrometers are used in magnetorheological fluids, in which case theparticle size is not uniform. If a magnetic field is applied to such amagnetorheological fluid, the carbonyl iron particles of themagnetorheological fluid are concatenated along the magnetic fieldlines, with the result that the rheological properties of themagnetorheological fluid (MRF) are considerably influenced depending onthe form and strength of the magnetic field.

WO 2012/034697 A1 has disclosed a magnetorheological transmissionapparatus having two components which can be coupled and the couplingintensity of which can be influenced. In order to influence the couplingintensity, a channel containing a magnetorheological medium is provided.The magnetorheological medium in the channel is influenced via amagnetic field. Rotating bodies, on which acute-angled regionscontaining the magnetorheological medium are provided, are provided inthe channel. The magnetic field from the magnetic field generationdevice can be applied to the channel or at least one part of the latterin order to selectively concatenate the particles and to wedge them withthe rotating body or release them. This magnetorheological transmissionapparatus can also be used on a rotary knob for operating technicaldevices. Such a magnetorheological transmission apparatus functions andallows very high forces or torques to be transmitted with asimultaneously relatively small design.

EP 1 168 622 A2 has disclosed, in FIG. 1, an electronically controlledfluid-filled rotary knob as a haptic operating element, a thin shearinggap which is filled with magnetorheological fluid being provided betweena rotationally fixed soft magnetic yoke ring and a likewise rotationallyfixed soft magnetic ring. A thin-walled and rotatable adjusting wheel isarranged in the shearing gap. A corresponding braking torque acts on thebasis of a magnetic field acting on the shearing gap. The disadvantageof this is the extremely extensive thin shearing gap which surrounds thestationary outer soft magnetic ring on the outside and inside, with theresult that the base friction is very high on account of the includedfluid (magnetorheological fluid=viscosity similar to honey). Inaddition, the adjusting wheel is predefined by the shape of therotationally fixed soft magnetic ring which is part of the magneticcircuit. As a result, the adjusting wheel cannot be produced from anydesired materials. FIG. 2 of EP 1 168 622 A2 discloses another exemplaryembodiment in which the adjusting wheel is used as return iron and is arotatable part of the magnetic circuit. The adjusting wheel completelysurrounds a stationary arrangement of a yoke iron, coils and a pluralityof yoke rings. The magnetic field runs radially through the shearinggap. The disadvantage is the thin shearing gap which is likewise veryextensive and is practically as large as the inner surface of theadjusting wheel. In addition, the adjusting wheel is part of themagnetic circuit and can therefore be produced only from particularmaterials having required magnetic properties. FIG. 3 of EP 1 168 622 A2discloses another exemplary embodiment having a rotating actuator and alaminated stator part which consists of soft magnetic material, has anarmature winding and produces a radially running magnetic field in amagnetically active gap between a radially inner stator part and aradially outer stator part. Both stator parts are connected to oneanother and consist of a soft magnetic material. The gap contains anannular and non-magnetic rotor which is connected to a bell-shapedoperating body via a shaft. The gap also contains a magnetorheologicalfluid. Around the shaft, the rotor has a bell-shaped rotor body, theannular wall of which engages in the gap between the radially innerstator part and the radially outer stator part. In this exemplaryembodiment as well, the shearing area between the rotor body and thestator parts is very large, thus producing a very high base torque.Operation using a finger is not possible in daily operation. Therefore,a haptic operating element according to EP 1 168 622 A2 is not suitablefor use as a sensitive haptic operating element.

It has been found during many tests that a haptic operating element canbe used commercially as a standard product for infotainment inautomobiles, for rotating actuators on smart devices or as an actuatoron devices (for example: oscilloscope), for example, virtually only whenthe base torque (idling torque with the magnetic field switched off;off-state torque) is less than 0.1 Newton meters (Nm). This applies totypical rotary knob diameters of 30, 40 or 50 mm. If a particularlysmall rotary knob diameter (for example<5 or 10 mm) is used, a basetorque considerably lower than 0.1 Nm is very advantageous andnecessary.

A base torque of less than 0.1 Nm cannot be easily achieved in astandard product with a magnetorheological basis. Brakes or clutcheswith magnetorheological fluid (MRF) can be used in steer-by-wire (largesteering wheel or large force introduction distance) or to brakeoperations in machines. In commercially available products, the basetorque is 0.4 to 0.6 Nm, that is to say a factor of 10 to 40 above theprior art of purely mechanical rotating actuators. The maximum torque ofthese units is between 5 and 12 Nm. The important factor between thebase torque and the maximum torque (operating range factor) is thereforein the range of 12 to 20 in the prior art. Therefore, no MRF operatingknob according to the MRF shearing principle has hitherto beenimplemented as a standard part in automobiles.

Haptic operating elements, in particular rotating actuators in vehiclesor on smart devices, require, for standard use which is accepted by theuser, a base torque which is many times smaller than in the prior art(MRF brakes according to the shearing principle); these base torques arebelow 0.2 Nm and better less than 0.1 Nm and ideally below 0.05 Nm.Fingers are very sensitive here. For comparison, the haptic operatingrange (a fine latching pattern) of a known and purely mechanicalrotating actuator (benchmark in automobiles) having a knob diameter ofapproximately 50 mm is between approximately 0.01 Nm (base torque) and amaximum torque of 0.05 Nm (peak ripple). A conventional infotainmentrotary knob in the center console (rotating actuator with a rotary knobdiameter of 50 mm, for example) with a base torque of 0.06 Nm is notaccepted by many automobile manufacturers (cannot be commerciallyimplemented). The necessary blocking (at least 5 Nm, for examplesimulation of an end stop or the position “P” in the gear selectorswitch) must then be produced using an additional locking pin(electrically actuated lifting magnet), for example.

A preferred object is therefore to provide an adaptive operatingelement, the braking torque of which can preferably be set between 0.02Nm (or less) and 5 Nm (=operating range) in the millisecond range. Afactor in the region of 250 between the base torque and the maximumtorque is therefore required, which is more than 12 times more than thatin the prior art.

In the automotive industry in particular, the intention is to reduce thenumber of operating knobs in the vehicle since the number has greatlyincreased on account of the multiplicity of functions. The aim is tosubstantially display only the currently required information andswitching options. On the other hand, the customer should not have toenter and browse the menus too much in order to be able to carry outnecessary functions. Therefore, the user must often be able to operate ahaptic operating element without the use of force.

The aim of the invention is therefore to improve the advantageousvariability and flexibility of haptic operating devices based onmagnetorheological media in such a manner that they can be used forsophisticated haptic operating elements.

The intention is to provide a haptic operating device having amagnetorheological transmission apparatus, thus enabling even moreflexible use.

A haptic operating device according to the invention is equipped with abasic body and a rotating unit, connected in particular to a shaft, anda magnetorheological transmission apparatus with at least two componentswhich can be coupled. The coupling intensity of the two couplablecomponents can be influenced. A magnetorheological medium which can beinfluenced by a magnetic field and has magnetically polarizableparticles is arranged between the couplable components for the purposeof influencing the coupling intensities. At least one magnetic fieldgeneration device preferably having at least one electrical coil forgenerating at least one magnetic field is provided in order to influencethe magnetorheological medium using the magnetic field. The magneticfield generation device is designed and set up to influence themagnetorheological medium using its magnetic field. The basic body iscoupled to one of the two components and the rotating unit is coupled tothe other of the two components. At least one rotatable transmissionelement is arranged in the channel as a magnetic field concentrator andis caused to rotate during a rotational movement of at least one of thecomponents which can be coupled. The rotatable transmission element canbe referred to as a rotating body or a magnetic field concentrator.

The magnetic field concentrator concentrates the magnetic field onto asmaller area. The transmission element may be in the form of a ball orroller, for example, without being restricted to these forms, andconcentrates the magnetic field, that is to say the magnetic field ischanged between the two components which are moved relative to oneanother and is concentrated from a large area onto a small area (atransition area). The ratio of these areas is considerably greater than1 and, in particular, greater than 2, greater than 5 or, in particular,greater than 10. In principle, this is the ratio of the cylindrical areaof the inner ring in relation to (the region of) the tangent edge of aroller or in relation to a ball point multiplied by a number of thetransmission elements, in particular 15, for example.

The transmission element concentrates the magnetic field and forms amagnetic field or flux density concentrator.

The transmission element is connected neither to the first component norto the second component in a rotationally fixed manner. The fieldconcentrator can move “arbitrarily” between the two components.

Such a haptic operating device according to the invention has manyadvantages. The haptic operating device allows a very small base torque,thus making it possible to easily rotate the rotating unit or a rotaryknob formed on the haptic operating device. An operator can convenientlyrotate the rotating part using his little finger. A base torque which isless than 0.1 Nm and, in particular, less than 0.07 Nm and preferablyless than 0.05 Nm is enabled, thus enabling convenient operation indaily use even if used frequently. It is not necessary to grip therotating part using the entire hand or at least two fingers in order torotate the rotating part (even repeatedly in succession). Simpletouching and rotating using only one finger also generally suffice.

At the same time, a simple structure is enabled and only few parts areused. As a result of the simple structure, in which torque istransmitted through the magnetorheological medium or magnetorheologicalfluid (MRF) only inside the channel at least to the greatest extent, aparticularly low base torque (base torque=torque needed for rotationwhen the electrical coil is switched off) can be achieved.

In contrast, a haptic operating element according to EP 1 168 622 A2 hasthe disadvantage that the base torque is very high because a very largeamount of shearing area is used. The ratio of active area to useful area(shearing area) is very unfavorable. The shearing gap must be small fortechnological reasons, which in turn greatly increases the friction(fluid friction). The active shearing gap filled with MRF is very large.

In the present invention, the channel has a large radial extent (channelheight), with the result that the base friction caused by the MRF perse, when the magnetic field is switched off or is low, is very low onaccount of the large radial extent. The large radial extent results in alarge channel area. In contrast to this, however, thetransmission/contact areas are very small. Only transmission elements(for example rollers) affect the moving and stationary parts. Thechannel is very large and has low fluid friction.

In the structure according to EP 1 168 622 A2, the very thin gapcontains MRF, which has substantially worse coefficients of friction onaccount of the iron particles and high viscosity (similar to chocolatesauce). The structure according to EP 1 168 622 A2 resembles a slidingbearing and the structure resembles a rolling bearing here. A basetorque of <0.1 Nm is not possible in the case of an MRF structureaccording to the shearing principle, which is intended to be able to becommercially used as a standard product.

In particular, the basic body comprises a base plate and an annularholding housing with a holding space arranged in the latter, the holdingspace being radially delimited to the outside by an outer limb of theholding housing extending substantially in the axial direction. Theshaft is preferably rotatably held centrally on the holding housing. Inparticular, the electrical coil is held in the holding space. Inparticular, a circumferential ring which is connected to the shaft in arotationally fixed manner adjoins the holding housing in a radiallyinner region and in a manner separated by a thin axial gap. The channelis preferably arranged in the holding space and is radially delimited tothe outside at least substantially or completely by the outer limb andis radially delimited to the inside at least substantially or completelyby the circumferential ring, with the result that a substantial part ofthe magnetic field from the magnetic field generation device runsthrough the holding housing, the channel and the circumferential ring.

At least one display unit is preferably assigned. The rotating unitpreferably surrounds a display unit at least in sections.

At least one actuation sensor for sensing an axial actuation forceand/or an axial actuation travel is preferably arranged on the basicbody and/or the rotating unit.

The cited haptic operating devices have many advantages. A hapticoperating device in which the rotating unit surrounds a display unit atleast in sections or else completely is very advantageous since the userhas a view of the display unit, in particular directly in the center ofthe rotating unit. As a result, the user can observe the changingdisplay of the display unit during rotation of the rotating unit andneed not allow his gaze to stray in order to track what effects therotation of the rotating unit has on the technical equipment such as, inparticular, a vehicle and particularly preferably a motor vehicle. Theuser can also rotate the rotating unit without looking at the operatingdevice and can possibly operate and actuate the rotating unit withoutvisual contact. However, the user always has the possibility ofascertaining, by means of a brief glance, the position in which therotating unit is currently situated and what is currently displayed onthe display unit of the haptic operating device. A considerable furtheradvantage is that the user can use his operating hand to partially covera display field behind it, whereas that display area of the display unitwhich is enclosed by the rotating unit is usually nevertheless freelyaccessible to the user's gaze.

When used in a motor vehicle, for example, the haptic operating deviceaccording to the invention makes it possible for the start menu(OFF-infotainment-ignition-start) to be hidden after the startingprocess since it is no longer required as long as the automobile ismoving. It is not even permissible to switch off or start the vehiclewhen the gear is engaged.

In the case of self-driving vehicles for example, there is a desire forthe gear shifter to disappear or for the gear shift etc. to be hiddenduring “self-driving”. In this case too, operation using the hapticoperating device can now be dynamically (adaptively) adapted to thesituation. Instead of the gear shift, it is possible to display theentertainment or, for example, parameters relevant to self-driving, forexample distance, response behavior of the sensors etc.

In the case of self-driving vehicles or during autonomous driving, itmay be problematic or dangerous if, for example, the vehicle containingthe driver as the passenger automatically parks and the transmissionselection lever for the gear shift remains here in the position selectedlast (for example “D”) for mechanical reasons even though the vehicle isin the reverse gear. It is no longer possible for the driver tointervene here since the displayed function does not match the executedfunction, which can confuse the driver. This also applies to the processof switching on the light (rotary switch) which is autonomous or isrequired during or for self-driving, the windshield wipers, the gaspedal, the brake pedal or other systems. Therefore, the practice ofmaking all switching elements active using servo motors is much tooexpensive. The invention provides a remedy since the gear shift can beautomatically changed to the parked position “P” when a vehicle isswitched off. In contrast, the rotating unit can remain in the positionin which it is situated when the vehicle is switched off. The next timethe vehicle is started, the current position is interpreted as “P”.

In the case of automobiles, owing to the concentration on the road, itis also necessary for particular operating elements to be able to beactuated virtually “without looking” (that is to say “blind”). Hapticfeedback additionally helps in this case.

The display unit is particularly preferably designed to display a symbolwhich is characteristic of a position of the rotating unit and is, inparticular, a graphical symbol. It is possible for the display unit todisplay an operating state of the rotating unit and/or of the apparatusto be operated, such as a vehicle or a motor vehicle. It is possible andpreferred for the operating state to be represented using a graphicalsymbol.

In all cases and configurations, the rotating unit can also be referredto as an operating unit.

A considerable advantage of a haptic operating device in which anactuation sensor for sensing an axial actuation is arranged is the factthat the haptic operating device cannot only be actuated by rotating therotating unit but can also react to axial actuation forces. In suchconfigurations having an actuation sensor, the actuation sensor isprovided on and is particularly preferably fastened to the basic bodyand/or the rotating unit, in particular. The actuation sensor may sensean axial movement of the rotating unit relative to the basic body.

In particularly preferred configurations, a haptic operating device hasa display unit on the rotating unit and at least one actuation sensorfor sensing an axial actuation force.

The display unit is preferably connected to the basic body in arotationally fixed manner, and the rotating unit is rotatable relativeto the display unit. Such a configuration has the advantage that adisplay on the display unit does not change its angle during rotation ofthe rotating unit. As a result, the display on the display unit remainsreadable for the user in unchanged form. However, it is likewisepossible for the display unit to be connected to the rotating unit in arotationally fixed manner and to be rotatable, together with therotating unit, with respect to the basic body. In the case of such aconfiguration, the viewing angle for the user does not change or changesonly slightly if it at least partially rotates together with therotating unit.

In preferred developments, at least one sensor which is used as an anglesensor is provided, which sensor can be used to sense an angle changebetween the rotating unit and the basic body. In this case, the sensoror angle sensor can detect relative angle changes. However, it is alsopossible for the sensor or angle sensor to sense an absolute anglebetween the rotating unit and the basic body. It is also possible forthe sensor or angle sensor to sense an angle of between 0 and 360° inabsolute terms, for example, but to be reset again after one completerevolution, with the result that angles of between 0 and 360° are alwayssensed during continuous rotation.

The sensor or the sensor used as an angle sensor preferably comprises atleast two sensor parts, one sensor part being connected to the rotatingunit and the other sensor part being connected to the basic body, inparticular. For example, one sensor part may be in the form of a pulsegenerator, a measuring tape, a scale or the like and the other sensorpart or the second sensor part may be used as a sensor or detector andmay sense a relative movement of the first sensor part.

In preferred developments, the sensor or angle sensor is designed tosense an absolute angle position between the rotating unit and the basicbody.

It is preferably possible to detect the direction of rotation. A highangular resolution is preferably possible. The finer the angularresolution, the earlier it is possible to recognize (or speculate) thewishes of the operator (reversal of the direction of rotation, fineradjustment). The control device (electronics/software) can reactaccordingly. A Hall sensor (EP 1 168 622 A2) is generally much tooinaccurate for this purpose since only a few hundred “counts/revolution”are possible. The sensor or angle sensor is preferably designed toenable an angular resolution of 0.2° and, in particular, at least 0.1°or 0.05° or better. Angular resolutions of more than 100,000“counts/revolution” (better than approximately 1/300 degree) aredesirable. With an angular resolution of better than 0.2° or 0.1°, amovement pattern can be derived from extremely small movements.

In the case of low sensor resolutions, the “operating element” or therotating unit or the rotary knob can remain with a “sticking” feeling (ahigh torque is needed for actuation), which haptically feels veryunpleasant and is therefore very disadvantageous. In the case of areversal of the direction of rotation at an end stop, for example, ahigh torque must then be initially applied even though the user wishesto carry out rotation in the opposite direction and a release cantherefore be effected. Only the control device must initially “notice”that rotation is being carried out in the opposite direction. In thiscase, a high angular resolution helps considerably.

The (visible) part of the rotary knob (visible part of the rotatingunit) particularly preferably does not form part of the magneticcircuit. The visible part of the rotary knob can particularly preferablyhave any desired design; the rotary knob can be chromium-plated or canbe made of plastic or glass or can be covered with leather etc. sincethe rotary knob is a “design element”. This also relates to the assemblysuitability (no screws visible; covering of the assembly hole etc.).

The transmission elements or rotating bodies (running rollers) arepreferably rounded or cambered on the end face so that they axially haveonly point contact with the base plate or the cover. This considerablyreduces the base friction and therefore the base torque.

It is possible to dispense with a contact ring.

The shaft is preferably magnetically conductive, thus reducing the size,weight and costs. The shaft preferably consists of a low-alloy steel,for example S235. So that the seal running thereon does not produce muchfriction and does not damage the shaft (race), the shaft is preferablyhard-chromium-plated.

The circumferential ring preferably consists of steel having goodmagnetic conductivity or soft magnetic steel and is connected to theshaft in a rotationally fixed manner, in particular pressed.

The operating knob or the rotating unit is preferably connected to theshaft via a torque transmission element, for example a square with aslot. The operating knob or the rotating unit is braced without play bythe torque transmission element (for example screwing using acountersunk screw).

In preferred developments and configurations, at least one controldevice is provided, the control device being suitable and designed todynamically control the magnetic field generation device. The magneticfield from the magnetic field generation device is preferablydynamically generated on the basis of a rotational angle in order toprovide a dynamic or adaptive and angle-dependent haptic latchingpattern. In this case, it is particularly preferred for the hapticoperating device to comprise the control device. The rotational anglecan be derived from a relative or absolute angle position. It is alsopossible for an angle change to be used as the rotational angle. Suchconfigurations are very advantageous since latching points at which therotating unit practically engages can be dynamically provided over oneor more angular ranges. It is also possible to dynamically generate endstops at which the torque needed for further rotation is considerablyincreased above a particular rotational angle in one direction ofrotation or the other.

A control device is preferably provided and the control device isdesigned to accordingly rotate a representation of contents of thedisplay device in the opposite direction on the basis of a signal fromthe sensor or angle sensor. Such a configuration is advantageous, inparticular, in the case of a co-rotating display unit since theorientation of the represented contents is left substantially unchanged.For this purpose, the representation of the contents of the display unitcan be rotated precisely by the same amount in the opposite direction bywhich the rotating unit is rotated. It is also possible for the rotationin the opposite direction to be carried out only to a certain extent. Inthese configurations, the represented contents on the display unit canremain substantially unchanged or even completely unchanged duringrotation of the rotating unit.

The contents of the display unit can also be changed in a mannercorresponding to the operator's viewing position. If the rotating unitor the operating element is operated, for example, by the driver in amotor vehicle, the display contents or the angle of the display contentsis/are oriented toward the driver (for example in the 8 o'clockposition). If the operating element is actuated by the front-seatpassenger, the display contents are accordingly oriented, that is to sayin the 4 o'clock position, for example. The haptic latching pattern orthe latching positions is/are also adapted in association with this.

In this case, the haptic latching pattern can also vary the haptictorque. This is advantageous because the driver will operate theoperating element with his right hand and the front-seat passenger willoperate the operating element with his left hand. For most people, thefeeling in the hands differs and this can be counteracted. Therefore,the latching pattern or the latching torque or the latching torqueprofile can be individually adapted to the operator via the rotationalangle.

The menu may be entirely different if, for example, children rotate it(they are identified using keys, a fingerprint in the cover, smartphone,smartwatch). In this case, only restricted operation may then bepossible (for example no hot temperatures, machines: no high speedsetc.) or operation of more sensitive, other latching patterns may bepossible.

In the case of machines in companies, for example processing machines,or in the case of copiers, the menu and the latching pattern can changeaccording to the operator. A warning can also be given via the hapticknob, which can prevent operating errors, particularly with newoperating personnel, for example.

At least one separate contact element is preferably arranged between thetwo components. Such a contact element is preferably in the form of acontact ring and is used, in particular, as a friction ring and may bein the form of an O-ring, for example. The friction ring is used as arotating ring and is preferably at least in occasional contact with atleast one component. The contact element may have, in particular, around cross section or else preferably a flat, flattened or elserectangular cross section.

Such a contact element or such a contact ring or friction ring makes itpossible to ensure reliable contact between the two components orrolling contact on one of the components. The contact ring isparticularly preferably elastic and can be produced or formed, forexample, from a rubber material or from a rubber-like material.

A channel is particularly preferably formed between the two components,and at least a plurality of rotating bodies are particularly preferablyprovided in the channel.

The contact element or the contact ring or at least one contact ring orfriction ring or friction element is particularly preferably arranged inan intermediate space or internal space between the two components. Inparticular, the contact element is arranged or fastened in the channelbetween the two components. For example, the contact element or thecontact ring may be arranged in a circumferential groove on one of thetwo components. It is also possible for a contact element or a contactring to be respectively provided on both components. At least onerotating body is particularly preferably in contact with at least onecontact element/contact ring.

It is also possible for at least one rotating body to be equipped withat least one contact element or contact ring. For example, all orsubstantially all rotating bodies may each be provided with a contactelement or contact ring. The contact ring may have any desired shape,for example a quad ring or a rectangular ring, without being restrictedthereto.

The contact elements/contact rings between the components and/or therotating bodies and the components ensure reliable contact between thecontact element/contact ring and the two components, thus ensuring that,in the case of a relative rotation of the two components with respect toone another, the rotating body co-rotates at least for most of the time.

Such a configuration is particularly advantageous if the intention is touse the wedge effect for wedging magnetorheological particles.

A configuration without the use of (flexible) contact elements orcontact rings enables even lower base friction and is thereforeparticularly preferred.

The basic body preferably comprises a base plate and a holding housing,and a shaft is rotatably held on the holding housing. Themagnetorheological medium is preferably held between the basic body andthe shaft. For example, the magnetorheological medium may be held in aninternal space of the holding housing.

rotating unit is preferably connected to the shaft in a rotationallyfixed manner. The connection can be effected using a force fit and/or aform fit.

In advantageous configurations, the shaft is rotatably supported at oneend on the base plate. In particular, the shaft is resiliently supportedon the base plate using one end. This makes it possible to preload theshaft in a defined position.

The basic body and the shaft preferably each have a circumferentialrunning surface for the rotating bodies adjacent to the base plate. Therunning surface(s) may be provided on a cylindrical, convex or concaveor else conical circumferential surface.

At least one running surface preferably has at least one circumferentialgroove for the rotating bodies and/or for at least one contact elementor at least one contact ring. This ensures that the contact ring and therotating bodies assume a defined position.

In advantageous configurations, the running surface of the shaft isformed on a circumferential ring with an increased diameter. Inpreferred developments, a holding space, in particular an annularholding space, in which an electrical coil is arranged as the magneticfield generation device, is formed in the holding housing. In allconfigurations, the electrical coil may also be arranged at otherlocations or at or in other forms of recesses.

The electrical coil is preferably arranged substantially axiallyadjacent to the rotating bodies. This makes it possible to ensure thatthe magnetic field generated by the electrical coil acts, to a highdegree, on the rotating bodies or the channel and the magnetorheologicalmedium contained in the latter.

The circumferential ring is preferably separated, on an end face, froman end face of the holding housing by a gap. A free axial distance inthe gap is preferably considerably shorter than a free radial distanceat the channel. The free radial distance at the channel results from theradial distance between the two components and, in particular, from thefree radial distance between the circumferential ring and the end faceor running surface in the holding housing. In particular, the end faceis an axial surface but may also be part of a lateral surface of a cone.A ratio of the free axial distance to the free radial distance ispreferably less than 1 to 2 and, in particular, less than 1 to 5 andpreferably less than 1 to 10.

In preferred configurations, the holding housing and the circumferentialring consist substantially or completely of a material with bettermagnetic conductivity than the base plate. This makes it possible toensure an effective flux of the magnetic field.

The actuation sensor preferably senses a distance or a measure of adistance between the basic body and the rotating unit.

In all configurations, it is preferred for a free distance between therotating body and the component or at least one component to be at leasttwice as large as a typical average diameter of the magneticallypolarizable particles in the magnetorheological medium. At least oneregion containing the magnetorheological medium is preferably providedbetween the rotating body and at least one component, the magnetic fieldfrom the magnetic field generation device being able to be applied tosaid region in order to selectively concatenate the particles and/orwedge them with the rotating body and/or release them.

The region which contains the magnetorheological medium and at which theparticles selectively concatenate and/or wedge with the rotating bodyhas an acute angle, in particular, in the activated state.

It is also possible for the magnetorheological particles to beconcatenated in the channel without using rotating bodies.

If rotating bodies are used, the region, in particular the acute-angledregion, between the rotating body and a component preferably tapers inthe direction of the relative movement of the component relative to therotating body.

In particular, the two components can be coupled to one anotherselectively and in a controlled manner.

In the sense of this application, the term “coupling intensity” isunderstood as meaning the coupling force and/or the coupling torquebetween the two components. If linear force transmission is desired, forexample, the coupling intensity corresponds to the coupling force. If atorque is intended to be transmitted, the coupling intensity is used tomean the coupling torque.

The viscosity of the magnetorheological medium can preferably be changedby the field, as a result of which it is possible to influence thedisplacement work needed for the relative movement of the componentsand/or rotating bodies which can be moved relative to one another.

Displacement work is also understood as meaning the displacement forceneeded to displace the medium during a relative movement.

A considerable and surprising advantage of the magnetorheologicaltransmission apparatus used results from the considerably intensifiedeffect of the magnetic field from the magnetic field generation devicein the channel. The acute-angled region containing the medium acts as alever and therefore virtually like a strong mechanical levertransmission, the lever considerably intensifying the effect of themagnetic field by a multiple. As a result, either the field strength ofthe magnetic field generation device can be reduced with an effect whichremains the same or else the effect of the magnetic field is intensifiedwith a field strength which remains the same or the effect is evenconsiderably increased with a reduced field strength. The acute-angledregion containing the medium increases the effect by a multiple, inparticular, if the magnetic field acts on the medium. In particular, themagnetic field acts at least occasionally on the acute-angled regionwhich contains the magnetorheological medium or is formed.

As a result of the fact that the rotating body is arranged at aconsiderable free distance from the at least one component, amacroscopic wedge which can be used to transmit strong clutch or brakingtorques can be produced. Considerable construction volume can be savedas a result of the completely surprising multiplication of the effect.The effect used is based on the wedge formation (cluster formation) andnot only the magnetorheological concatenation of individual particles.The typical reaction time for the wedge formation requires severalmilliseconds, while individual particles are concatenated according tothe MRF effect already within approximately 1 millisecond. This timeduration, which is multiple times longer, is due to the wedge formation.Such a considerable intensification of the effect was not expected. Thelonger reaction time of, for example, 5, 10, or 20 milliseconds is morethan sufficient in many applications.

The channel can also be an intermediate space or a space which is openon four sides.

An acute-angled region of the channel is defined as that channel regionwhich appears approximately to have an acute angle in at least one crosssection through the shape of the rotating body and components. The sidesof the region do not have to be straight and can also be curved and/orhave another contour. The acute-angled region defines that part of thechannel in which the rotating body and components are at the shortestdistance from one another, in particular, or touch, and the adjoiningregion, in which the surfaces of the rotating body and components moveaway from one another.

Under the effect of a magnetic field, the acute-angled region containingthe magnetorheological medium is formed, in which a considerablyincreased viscosity is present.

A good torque to weight ratio, which can be greater than 100 Nm/kg, ispossible.

A rotating body is preferably set into a rotational movement by arelative velocity in relation to at least one component. It is possiblefor the circumferential velocity of the rotating body to be equal to therelative velocity in relation to the component. However, it is alsopossible for the circumferential velocity of the rotating body on itsouter surface to be greater than or less than the relative velocity. Inparticular, it is possible for the circumferential velocity of therotating body on its outer surface to be less than the relative velocityof the rotating body in relation to the component.

The rotating body can be designed to be substantially rotationallysymmetrical around at least one axis of rotation. It is likewisepossible for the rotating body to be designed to be rotationallysymmetrical around a plurality of axes of rotation. For example, therotating body can be in the form of a sphere or ellipsoid. It is alsopossible for the rotating body to be in the form of a cylinder, roller,or generally a rolling body. In particular, an approximately cylindricalconfiguration has proven to be advantageous since, in the case of acylindrical rotating body, for example, the acute-angled regioncontaining the medium forms over the entire width of the rotating bodyand is thus substantially wedge-shaped. In these and otherconfigurations, the acute-angled region has a wedge shape.

However, it is not necessary for the rotating body to be rotationallysymmetrical. Rotating bodies having elliptical or egg-shaped crosssections or rotating bodies having indentations like golf balls orhaving regular or irregular indentations and/or protrusions can alsoadvantageously be used. The surface of the rotating bodies can besmooth, but does not have to be. Since the rotating bodies are not usedto mount and support the components relative to one another, asymmetrical and/or smooth surface is not necessary. Rotating bodieshaving a rough and/or irregular surface can even be advantageous sincethe wedge effect is intensified. Increased wear does not occur since therotating bodies are not used for mounting and transmitting load-bearingforces.

The effect is preferably not intensified solely due to intensificationor bundling of the magnetic field, but rather above all also due to theparticles clustered in front of the rotating bodies or rollers and thecompaction thereof. Owing to the magnetic field, the particles cannotmove away and thus compact more rapidly to form a wedge. The wedge canbe externally controlled easily via switch. The advantage in the case ofmagnetorheological fluids such as MRF is that the wedge can disengageagain by canceling the magnetic field. The wedge can be influenced usingthe magnetic field—without mechanical movement or force introduction. Ithas proven to be advantageous for targeted influencing and reliablecontrol that the free distance between the rotating body and thecomponent is greater than a multiple of the particle diameter.

The diameter of the particles of the magnetorheological medium isbetween 1 μm and 10 μm, in particular. The typical mean diameter of theparticles of the magnetorheological medium is the arithmeticallyaveraged diameter of the particles which are larger than the smallestpercent and which are smaller than the largest percent. As a rule, thisvalue corresponds to the mean value of the diameters of the largest andthe smallest particle, that is to say 5.5 μm in the selected example.If, however, for example, a very small number of even smaller particlesare present, this does not change the typical mean diameter thusdetermined. The same applies if, for example, individual particleshaving a diameter of 10.5 μm or 11 μm are to be included.

The free distance between the rotating body and the component ispreferably greater than 30 μm and, in particular, less than 300 μm. Thetypical mean diameter of the particles is preferably between 3 μm and 7μm. The free distance between the rotating body and the component ispreferably greater than 70 μm and, in particular, less than 250 μm.

The acute-angled region advantageously wedges the two components, whichare freely movable relative to one another without a magnetic field,upon application of a magnetic field. A mechanical wedge in the form ofa separate fixed part is not required for this purpose.

The acute-angled region is preferably provided between the body and onecomponent in such a manner that the acute-angled region tapers in thedirection of the relative movement of the component relative to therotating body. If a cylindrical rotating body rolls on a flat surface ofone component, the acute-angled region forms in a wedge shape in frontof the rotating body. A wedge which is concatenated as a whole andinhibits the relative movement of the rotating body to the componentarises due to the concatenation of the particles in the medium.

The rotating body and, in particular, each rotating body is particularlypreferably in the form of a separate part between the first and secondcomponents. It is then preferred for one component, as the outercomponent, to surround the other component, as the inner component. Forexample, a (drive) shaft can be provided as the inner component. Theother or outer component can be used for braking, for example, and canradially surround the shaft. The rotating bodies can be provided betweenthe shaft and the outer component. It has been shown that rotatingbodies which rotate around their own axis are considerably better forachieving the wedge effect. Finished bearing shells are not necessary.The transmission of a clutch or braking torque functions independentlyof the quality of the rolling surfaces.

At least one separate bearing or roller bearing is provided for mountingthe two components. The rotating bodies ensure, with the wedge effect,the transmission of the desired torques, while the roller bearing orbearings ensure(s) the defined guiding and support of the two componentsand the uniform running gap.

A transmission may also be arranged or kinematic levers can be usedbetween the drive shaft and the rotating body or between the rotatingbody and the basic body/housing. As a result, the torque and therotational angle can be varied in a wider range or the haptic operatingknob can have a smaller construction and the construction volume cantherefore be considerably reduced. The transmission may be in accordancewith the prior art, preferably a planetary transmission or harmonicdrive which is free of play as far as possible.

In all configurations, the free distance is preferably at least twice,five times and, in particular, ten times as great as the largest typicalparticle diameter. In specific configurations, a free distance ofbetween approximately five times and, in particular, ten times andtwenty times the largest typical particle diameter has proven to beadvantageous. In the case of larger free distances, the maximumtransmittable torque is reduced again since the wedge effect subsides.In the event of excessively short free distances, a blockade can occureven without a magnetic field. In addition, disengagement of the wedgeafter the shutdown of the magnetic field then cannot always be ensured.

The mean particle diameter is understood as meaning the arithmetic meanof minimum and maximum particle diameters. Most MRF have magneticallypolarizable particles which have a size distribution of betweenapproximately 1 μm and 10 μm. The mean particle diameter is 5.5 μm inthis example. In the case of variable size distributions, the largesttypical particle diameter is understood as meaning a particle diameterwhich is exceeded by only fewer than 1% of the particles. The largesttypical particle diameter is somewhat less than 10 μm in the mentionedexample, so that 10 μm can be presumed to be the largest typicalparticle diameter here.

The free distance is preferably greater than 1/500 and preferablygreater than 1/250 and, in particular, greater than 1/100 andparticularly preferably greater than 1/50 of a diameter of at least onerotating body, and, in particular, the free distance is less than 1/10and, in particular, less than 1/20 of the diameter of the rotating body.

The free distance is preferably greater than 1/300 of the externaldiameter of the inner component and/or greater than 1/500 of theinternal diameter of the outer component. The free distance ispreferably greater than 30 μm and in particular less than 200 μm.

Variations by +/−20% are preferably possible in the case of all numericspecifications. A particle is understood below as meaning a magneticallypolarizable particle.

If oversized rotating bodies and/or shaft diameters are used, otherdistances can be advantageous. An advantage of this magnetorheologicaltransmission apparatus having at least two components which can becoupled is that the wedge formation is manufacturing tolerant, that isto say, for example, manufacturing-related and installation-relateddifferences in gap heights, surfaces, dimensions and also thermalexpansions or load-related shifts of components have a minor influencethereon and cause negligible torque or force differences.

For example, a structurally related change of the gap within certainsystem limits can also be detected by sensors and worked out by fieldadaptation, for example.

In preferred configurations, the rotating body is part of the first orthe second component. This means that the rotating body, which is in theform of a rotating body, for example, is part of the first component androlls on the second component, for example. The rotating body can alsobe without mechanical connection to both components, however.

In the acute-angled region, which is wedge-shaped, for example, theferromagnetic particles concatenate in the medium upon application of anexternal magnetic field and result in a locally more solid structurewhich opposes the further relative movement between the rotating bodyand the adjacent component. The particles in the wedge-shaped part canbe additionally compacted in the direction of movement in front of therotating body by the rolling movement of the rotating body. However,depending on the design of the rotating body, this compaction can alsobe performed by pitching, tilting, or other movements relative to acomponent.

For example, if the rotating body rolls on the surface of one componentand such an acute-angled region forms in front of the rotating body,particles in the medium are entrained and set into rotational movementby the outer surface due to the rotational movement of the rotatingbody, but the hardening acute-angled region strongly opposes such arotational movement. The acute-angled region in wedge shape results in aforce on the rotating body away from the component. Such a force and amovement resulting therefrom can optionally also be used for fineadjustment purposes. A rotational movement can preferably be convertedinto an axial displacement of the rotating body by the acute-angledregion in wedge shape when the magnetic field is activated. The rotatingbody is thus virtually caused to float by the particles. It is alsopossible to provide the rotating body or a component with thread-shapednotches, for example, or to mount them at an incline relative to oneanother, in order to change the effective direction of the resultingforce or to further increase the achievable force transmission. A linearmovement can thus be converted into a rotational movement using a typeof threaded rod. The relative movement is inhibited by applying a field.

It is likewise preferred for the rotating body to be in the form of aseparate part between the first component and the second component. Sucha configuration can be particularly advantageous since two acute-angledregions or wedge-shaped regions can occur between the rotating body andthe two components. If the rotating body practically rests against thefirst component on one side and practically rests against the secondcomponent on the other side, acute-angled regions which are subjected tothe magnetic field from the magnetic field generation device form onboth sides. The effect is thus increased. It is not necessary for thispurpose for the rotating body to rest completely against the firstcomponent or the second component. A small gap remains between therotating body and the respective component. The size of the gap isdependent, inter alia, on the properties of the medium. In particular,the size of the gap can be at least five times and preferably at leastten times or twenty times a typical or mean particle diameter.

The ferromagnetic particles consist, in particular, of carbonyl ironpowder. The fluid can be an oil, for example.

It is also possible for magnetorheological and electrorheological mediato be used jointly. The use of other media which are influenced andconcatenated, for example, by corresponding fields is also conceivable.It is likewise possible to use media which change their rheologicalproperties depending on other physical variables such as temperature orshear velocity.

The channel can be completely or also only partially filled with themedium. At least the acute-angled region of the channel is preferablyfilled with the medium.

In all configurations, the first and/or second component can berotationally symmetric. For example, the components can each be in theform of plates or cylindrical bodies, between which rotating bodies areprovided, in order to increase the effect of the magnetic field from themagnetic field generation device accordingly through the wedge effect.

In all configurations, it is preferred for the magnetic field to runthrough the rotating body and, in particular, substantially transverselyto the relative movement of the components relative to one another andfrom one component to the other component at least partially through therotating body. Such a configuration has proven to be particularlyeffective since the effect of the magnetic field at the transitionpoints from the rotating body to the walls of the channel isparticularly strong. Depending on the acting magnetic field, it istherefore advantageous if the rotating body is at least partiallymagnetically conductive. In particular, at least one component and inparticular both components and/or the at least one rotating body is/aremade at least partially of a ferromagnetic material. The relativepermeability is preferably greater than 500. The relative permeabilityof the material can also be 1000, 2000, or more. Rotating bodies made ofa ferromagnetic steel, such as ST37, are possible, for example.

The material can be demagnetized by a damped magnetic alternating field,so that a lower base torque is achieved without a residual field.

In all configurations, it is preferred for the magnetic field generationdevice to comprise at least one permanent magnet and/or at least onecoil. It is also possible to use one or more permanent magnets and oneor more electrical coils.

It is possible and preferred to permanently change the magnetization ofthe permanent magnet by means of at least one magnetic pulse from anelectrical coil. In such a configuration, the permanent magnet isinfluenced by magnetic pulses from the coil such that the field strengthof the permanent magnet is permanently changed. The permanentmagnetization of the permanent magnet can be set by means of themagnetic pulse from the magnetic field generation device to an arbitraryvalue between zero and the remanence of the permanent magnet. Thepolarity of the magnetization is also variable. A magnetic pulse forsetting a magnetization of the permanent magnet is, in particular,shorter than 1 minute and preferably shorter than 1 second and thelength of the pulse is particularly preferably less than 10milliseconds.

As an effect of a pulse, the shape and strength of the magnetic fieldare permanently maintained in the permanent magnet. The strength andshape of the magnetic field can be changed by means of at least onemagnetic pulse from the magnetic field generation device. The permanentmagnet can be demagnetized by a damped magnetic alternating field.

AINiCo, for example, is suitable as a material for such a permanentmagnet with variable magnetization, but other materials havingcomparable magnetic properties may also be used. In addition, it ispossible to produce the entire magnetic circuit or parts thereof from asteel alloy with strong residual magnetism (high remanence) instead of apermanent magnet.

It is possible to use the permanent magnet to generate a permanentstatic magnetic field which can have a dynamic magnetic field from thecoil superimposed on it in order to set the desired field strength. Thecurrent value of the field strength can be varied arbitrarily by themagnetic field from the coil. It is also possible to use two separatelycontrollable coils.

In all configurations, it is preferred to provide at least one controldevice. It is also possible to use an energy store, for example acapacitor, to store at least a fraction of the required energy. At leastone sensor or a plurality of sensors can be used to detect relevantdata, for example the relative velocity of the components in relation toone another or the prevailing field strength and the like. It is alsopossible to use a temperature sensor as the sensor, which triggers analarm if predetermined temperature conditions are exceeded, for example.A rotational angle encoder can advantageously be used to have datarelating to the angle position of the components in relation to oneanother at any time.

In all configurations, it is preferred that the permanent magnet atleast partially consists of a hard magnetic material whose coercivefield strength is greater than 1 kA/m and, in particular, greater than 5kA/m and preferably greater than 10 kA/m.

The permanent magnet can at least partially consist of a material whichhas a coercive field strength of less than 1000 kA/m and preferably lessthan 500 kA/m and particularly preferably less than 100 kA/m.

The magnetorheological transmission apparatus is part of an operatingdevice which comprises, in particular, an operating or control knob orthe like.

The rotating body and at least one component can touch at at least onepoint or on at least one line. It is possible and preferred for therotating body to be at rest relative to at least one component.

The rotating body can preferably move relative to at least onecomponent, for example in the form of a rotational or tilting movement.

The field strength can have a strong gradient depending on therespective distance between the rotating body and components.

The field strength preferably increases in the acute-angled regionbetween the rotating body and components toward the region having theshortest distance.

The need for maintenance is low since few and simple parts are used. Ifnecessary, the maintenance can be carried out by simply replacing themagnetorheological fluid. The structure is simple and robust and powerfeedthroughs are not required. In addition, the energy requirement islower than in the prior art because the wedge effect substantiallycontributes to influencing the relative movement of the components. Itis possible to achieve a torque/weight ratio of >100 Nm/kg.

In magnetorheological clutches or brakes without a wedge effect, themagnetic field poles move relative to one another and generate shearforces (direct shear mode) in the interposed MR fluid. The shear forcesvary depending on the magnetic field. No magnetic field means no or lowshear forces (no chain formation in the MRF), maximum magnetic fieldmeans maximum shear forces and therefore maximum braking force orbraking torque. In simplified form, the magnetic field and shear forcesare proportional.

In the present invention, through appropriate design of the individualcomponents, dimensioning, and field introduction, a very advantageousbehavior which deviates therefrom can be provided. This advantageousbehavior is expressed in that a substantially lower magnetic field, andtherefore a lower current intensity, is needed to maintain theacute-angled embodiment or the MR fluid wedge than is needed for theinitial generation of the wedge. This is because the particle cluster nolonger falls apart so easily once it has first been accumulated and hasbeen quasi-mechanically compacted by the special movements fundamentalto this invention under the influence of a correctly introduced magneticfield. As a result, for example, after a corresponding time forachieving this state, a braking torque can be maintained using thefraction of the magnetic field or electrical power (coil current), whichis advantageous in terms of energy.

If clutches having magnetorheological fluids according to the prior artare loaded beyond the maximum transmittable clutch torque, individualparticle chains begin to break apart, whereby slip or slipping throughresults. The maximum clutch torque is maintained, however, or sometimeseven slightly increases, and the clutch does not disengage. Depending onthe application, this can be undesirable, for example if a drill bit ofa drill jams during drilling.

In the present invention, through appropriate design of the individualcomponents, dimensioning, and field introduction, a very advantageousbehavior which deviates therefrom can be provided. This advantageousbehavior is expressed in that, if a maximum force is exceeded betweenthe moving parts, the wedge (material cluster) generated by the magneticfield is suddenly pressed through the gap (material displaced) and theforce decreases suddenly at the same time. On account of the relativemovement resulting therefrom and the high applied force, a new wedgedoes not form, as a result of which the relative force remains low. Inthe case of overload clutches, this behavior is very advantageous. Themaximum force (triggering force) or the maximum torque (triggeringtorque) can be preset via the magnetic field.

Furthermore, demixing, sedimentation, and centrifugal force problems arereliably avoided since continuous mixing of the particles in the mediumis achieved by the rotating bodies which are rotating.

On account of the substantially higher transmittable torques and forces,it is possible to implement clutches, brakes or the like havingsubstantially smaller diameters. On account of the low MRF channelheight and the rotational movement of the rotating bodies, demixing ispractically not relevant in the case of the present invention.

The invention can be used in manifold ways. Use as an operating elementon domestic appliances such as washing machines and also to choose theoperating state of vehicles is possible.

The invention can also be used in the case of a three-dimensionalmovement. The rotation and pendulum movement can thus be restricted orblocked by the MRF wedge. The acting torque is continuously adjustableand switching times in the range of a few milliseconds can be achieved.The structure is simple and no mechanically moving parts are requiredfor varying the torque. A further advantage is that almost noiselessoperation is possible. The additional costs are low and amagnetorheological transmission apparatus according to the invention canbe designed to be operationally reliable if, for example, a permanentmagnet with remanence is used to set a magnetic field. The wedge effectenormously intensifies the effect, with the result that a smallerinstallation space is achievable.

In all configurations, the rotating bodies do not have to be smooth, butrather can have rough or uneven surfaces.

The haptic operating device can be used in manifold ways and comprises,for example, controllers for crane operation or the like. In this case,the rotation can be controlled more stiffly, depending on the load. Itcan also be controlled on the basis of the load height.

The use in “force feedback” applications or in “steer by wire”applications, such as in the steering wheel, gas pedal or brake pedal,is also of interest. The use on operating elements in vehicles, steeringwheels, automobile radios, windshield wiper switches, home appliances,stereo systems, remote controls, cameras, test stands, oscilloscopes,operating apparatuses, robot controllers, drone controllers and whenpositioning military weapons etc., is also possible.

In all configurations, it is also possible to use magnetic seals to sealan apparatus according to the invention, in addition to a seal with asealing lip. The seal can be produced via a permanent magnet here.Advantages of such a configuration are smaller base forces, freedom fromwear, and the permissibility of greater manufacturing tolerances. Inaddition, there is a defined overload behavior since a definedbreakthrough occurs if the overload is exceeded. It is possible to usesuch a seal in front of or behind an apparatus according to theinvention or to use it in front and behind.

A significant advantage of the magnetic seal is the very low friction;however, it can be necessary to use yet another seal since such a sealpossibly only holds back MRF particles and allows oil as the base fluidto pass through the gap over time, for example. Therefore, such amagnetic seal can be used as an outer seal in order to hold back MRFparticles. A further seal, for example a conventional seal, then onlyseals off the carrier medium.

A movement of the magnet can be used to achieve lubrication in the MRF,as well as material transport and cooling, for example via hydrodynamiceffects. In addition, a flow away from the seal can be achieved andpressure differences can be dissipated.

In order to set the play between two parts, for example, or to removeplay from a design and to compensate for manufacturing tolerances, forexample, it is possible to use a force or an axial force and/or a radialforce which is caused by an MRF wedge effect.

In all configurations, it is preferred to provide a settable permanentmagnetic field strength via remanence. In preferred embodiments, abearing having a magnetorheological transmission apparatus according tothe invention has no or only minimal residual magnetism (remanence)itself. Otherwise, a position-dependent counterforce of differentstrength can occur since the parts move in relation to one another.

In advantageous configurations, the remanence material should bearranged in a general region of the bearing which is permeated, inparticular, by the magnetic field in a position-independent manner,thus, for example, the inner shaft or the outer shell etc.

However, it is also preferred to use the effect of theposition-dependent magnetization by using, for example, the innerrunning surface having remanence in order to generate specific latchingtorques, for example. This can be performed, for example, for hapticfeedback about variable latching torques with respect to their strength,the rotational angle, or the end stop or the like. Not all bearing ballshave to be ferromagnetic, depending on the desired setting capability.

It is also possible to provide a magnetorheological transmissionapparatus having a design deviating from the conventional bearingstructure. For example, the direction of the magnetic field can also beoriented at least partially or completely approximately parallel to theaxis. At least partial orientation parallel to the rotational directionor movement direction or in the tangential direction is also possible.It is also possible for the entire magnetic circuit to be arrangednearly or completely in the interior or on the end face.

The material of the magnetorheological transmission apparatus does nothave to be completely ferromagnetic; depending on the desiredapplication or magnetization, it can be advantageous if individual partsof the magnetorheological transmission apparatus are not ferromagneticor are only partially ferromagnetic.

Depending on the application, it is also conceivable to manufacture atleast one part from different materials, to obtain locally differingmagnetic properties.

The haptic operating device preferably functions with amagnetorheological transmission apparatus with a wedge effect. Theposition or the rotational angle of the rotary knob can be determinedvia the rotary encoder and the rotational resistance can be varied in awide range. Thus, for example, a haptic interface with variable latchingtorques and arbitrarily settable end stop can be constructed, whichchanges its properties depending on the currently selected menu. A lowor high torque and/or a small or large latching pattern/ripple and alsoa variable latching pattern—depending on the menu to be operated—can beset. The profile of the torque increase and decrease can be set orvaried depending on the situation, for example as a square-wave,sinusoidal, sawtooth, or arbitrary profile. A stop can also besimulated. The stop can be hard or can have a predefined orsituation-dependent torque profile. The torque profile can be differentduring rotation in one direction than during rotation in the otherdirection.

The rotary knob as one component is preferably fixedly connected to theshaft as the other component which is in turn rotatably mounted in thehousing. The relative movement or relative position is detected via arotary encoder, for example via a magnetic, optical or (via buttons)mechanical incremental encoder. A potentiometer with sliding contactscan also be used, but only specific rotational angles are usuallypermissible using said potentiometer.

A sealing ring is advantageous so that the magnetorheological fluidremains in the housing. The seal can also only consist of permanentmagnets or a combination of a permanent magnet and a conventional seal.

The inner region, i.e. the volume enclosed by the seal and housing, isat least partially filled with a magnetorheological fluid.

The housing is preferably designed as a pot, i.e. it is closed on oneside. Only one sealing ring is thus required. A continuous shaft(two-sided shaft) is also conceivable.

The coil can generate a magnetic field, wherein the magnetic circuit isclosed via the housing, the shaft, and the magnetorheologicaltransmission apparatus. The magnetic field required for the wedge effectcan thus build up in the magnetorheological transmission apparatus. Thecoil is advantageously fixedly connected to the housing, which makes thecable routing easier.

The structure is robust and can be designed such that almost no magneticstray fields are generated outside the housing. However, many otherstructure variants are conceivable, which can have specific advantagesdepending on the application.

For example, the coil can also be arranged outside the housing, themagnetic field then acting on the magnetorheological transmissionapparatus through the housing. No mechanical connection is necessaryhere between the coil and the housing; the coupling of the magneticcircuits is sufficient to influence the magnetorheological transmissionapparatus in the housing. In particular, the coil does not have to bepermanently on or in proximity to the housing and can be designed suchthat it can be removed from the housing as a separate unit. Permanentmagnets can also be provided in the magnetic circuit.

In a preferred embodiment, the rotary knob can be electromagneticallydriven, for example, and can also actively exert a force (forcefeedback) in order to be able to statically generate a specificcountertorque. In this design, a better torque to installation spaceratio is achieved than in many designs according to the prior art. Inaddition, the production costs are low because of the simple structuresince, for example, the rolling surfaces of the components do not haveto be highly precise in haptic applications and also generally do nothave to withstand high speeds and a large number of revolutions. Ingeneral, the magnetorheological transmission apparatus described herehas a very low base friction (OFF state). A battery and a controlcommand transmission unit (radio, WLAN, Bluetooth, NFC, antenna) arepreferably also integrated in the actuator or rotary knob. The hapticknob can then be placed anywhere and does not require a wired controlconnection or current connection. The MRF wedge principle requires verylittle current (power) in relation to the torque. It is therefore alsohighly suitable for battery operation or for wireless energy supply.Both the required energy and control commands and also, for example,measured values from sensors such as rotational angles can betransmitted wirelessly.

A preferred embodiment manages without a battery and receives the energyrequired for the function by means of inductive coupling. Embodimentswhich acquire the energy required for operation directly from theenvironment and buffer it locally (energy harvesting) are alsoparticularly preferred. Thermoelectric generators, solar cells, elementswhich convert vibrational energy into electrical energy, and others, aswell as corresponding local energy stores are possible for the energyconversion. It is also conceivable to use the movement of themagnetorheological transmission apparatus itself to generate energy.

If a magnetic field is applied to the magnetorheological transmissionapparatus at least partially via a permanent magnet, and themagnetization of the magnetic field is permanently changed by at leastone magnetic pulse from at least one electrical coil, several advantagesresult. In specific cases, weight and space advantages can be achieved,for example by using the remanence and the pulsed operation of a coilwhich does not always have to be energized. The wires of the coil can bedimensioned to be thinner and lighter because they are each energizedonly for a short operating time. This can result in advantages in thecase of weight, power demand, space requirement, and costs.

Therefore, it can be advantageous in specific applications that, due tothe pulsed operation of the electrical coil, it can be significantlysmaller than if it must be designed for a switched-on duration of 100%.The heating of the coil usually does not play a role in pulsed operationsince short-term power loss peaks are buffered by the intrinsic heatcapacity of the coil and the parts surrounding the coil. Very highcurrent densities in the turns can thus be tolerated or thinner linescan be used, as long as the mean power loss remains acceptable overlonger periods of time.

In the case of a smaller coil, the magnetic circuit surrounding the coilcan also usually be smaller, which is why a comparatively large amountof installation space, material, weight, and costs can be saved. Onlythe energy expenditure for a single pulse increases here, but this canbe very well tolerated depending on the application.

Overall, a large amount of energy can nonetheless be saved in comparisonwith a continuously energized coil.

In all configurations, it can be possible to supply the power in awireless manner. The power can be supplied, for example, from thecurrent source to the power electronics or from the power electronics tothe coil via electrical, magnetic, or electromagnetic coupling, forexample a radio link. When used in a bicycle, the power can be suppliedexternally via a docking station, for example. It is also possible tosupply energy to all loads (forks, rear shock absorbers, display) via anenergy source on a bicycle, for example. The power can also be suppliedsimilarly in the case of a ski boot, ski, mobile telephone, or to thesensors.

An energy supply via radio can possibly have worse efficiency thanconventional wiring. In addition, the energy transmission and its rangecan be limited. However, such disadvantages do not interfere dependingon the application. It is advantageous that no wear of the contactsoccurs. The energy transmission is usually secure from polarity reversaland short-circuit-proof since only a limited power is present on thesecondary side. Furthermore, cable breaks are not possible and theapparatus is more movable as a whole.

In such configurations, however, it is advantageous to buffer the energyfor at least one pulse in a capacitor or energy store. The energy supplyof the system can thus have a smaller power since short-term power peaksof a pulse are absorbed by the capacitor. In addition, a discontinuousor pulsed energy supply can also be used.

One possible expansion stage of the present invention is a fullyautonomous system which is wirelessly supplied with energy. For example,use on a bicycle is conceivable, in which case the system is suppliedwith energy by at least one small magnet on a tire.

In general, arbitrary “energy harvesting” units can thus be used tosupply energy, for example solar cells, thermoelectric generators, orpiezoelectric crystals. Elements which convert vibrations into energycan thus also be used very advantageously for the supply.

An embodiment similar to that in an electric toothbrush is alsoconceivable, in which the energy is supplied by inductive coupling. Forexample, the rechargeable battery can be inductively charged, withoutdamaged cables or corroded or soiled contacts obstructing the chargingprocess. Energy can be transmitted over longer distances via magneticresonance.

The power supply of the remanence pulse can be effected via induction,as in the case of electric toothbrushes. The combination of the MRFwedge principle with remanence is particularly power-saving andadvantageous.

A loudspeaker or a noise generating unit can also be integrated orassigned. This is advantageous since the rotary knob as the MRF wedgeknob is mechanically noiseless per se. Both the rotation without andalso with a latching pattern and/or the virtual stops are noiseless perse. The generation of the MRF wedge for a torque increase or to generatea latching pattern is likewise noiseless per se. By means of the noisesource, such as a loudspeaker or a piezoelectric loudspeaker, forexample, clicking can be associated with the virtual latching pattern ateach latching position. The type, volume and duration of the noise canbe individually assigned, but can also be changed or turned off if theuser wishes.

Therefore, the torque, the latching pattern, the stops and the noise areprogrammable or adaptive. The noises can also be generated via externalloudspeakers, for example standard loudspeakers in the automobile or theloudspeakers of the hi-fi system in the home.

The haptic knob can therefore practically replace the mouse wheel of acomputer mouse. In the case of the latching pattern, not only theangular distance of the latching pattern can be settable, but ratheralso its profile shape, thickness etc. A latching pattern characteristiccurve can therefore more or less be predefined.

The haptic rotary knob can also be mounted on an operating surface or ona screen. So that the display does not have to be removed for fasteningthe knob, it can consist of an upper part on the display and a lowerpart below the display. Data transmission via induction or the like, forexample, is preferably provided. The display can thus be produced morecheaply as a surface.

It is also possible for an MRF haptic knob to also be pressed. Thepressing can also act through an MRF whose properties are variable via amagnetic field.

The screen displays the information to be set which changes depending onthe application. The function of the haptic knob is adapted thereto. Inone case, adjustment is made by means of a latching pattern (for examplesetting the volume; a volume scale which can also have a logarithmicscale appears on the display).

In another case, adjustment can be made between two positions without alatching pattern, but with variable torque, thus, for example, betweenthe 8:00 position and the 16:00 position or between the 4:00 positionand the 8:00 position, in which case an increasing torque can beprovided in each case before the end position. The latching pattern canalso be used to approach defined positions, for example if a name inputis requested.

The display can also be in the form of a touchscreen. Menu items canthus be rapidly selected and fine adjustments can be made by means ofthe rotating actuator. For example, it is not desirable in the case ofautomobiles to control the volume of the radio via touchscreen since thedriver would otherwise always have to look for a long time at what andwhere he is currently adjusting, which distracts him. He also finds therotating actuator with a brief glance or without looking at it.

The haptic operating element can also be globally displaceable on guidesor kinematic levers. The haptic operating element which has a verycompact and low construction can therefore be mounted above a display,for example. Depending on the position of the haptic operating deviceabove the display (almost like the mouse pointer of a screen mouse), theunderlying menu is haptically and dynamically adapted.

The adjustment using a mechanical actuator is also simpler and saferthan via a touch display when cycling, for example. This is also true,in particular, if the cyclist is wearing gloves, for example, wherebythe operation of a touch display is difficult or even impossible.

A combination of a display or touch display and a mechanical rotatingactuator with variable torque/latching pattern is also possible. Suchinput devices can also be advantageous outside the motor vehicle, thus,for example, in the case of controllers for industrial installations,remote controls for televisions or radio vehicles such as toyhelicopters, for example, and on PCs and games consoles, and controlconsoles for military applications (drone aircraft, rockets).

It is also possible for a haptic rotary knob with a display to replacethe current computer mouse.

It is possible for the rotary knob or the actuator to be countersunk inthe normal state and to be extended only if needed.

It is also possible to embody such a structural unit as a slidecontroller, in particular in combination with a linear MRF wedge unit.

It is also possible to equip a magnetorheological transmission apparatuswith one or more poles and one or more elevations. In allconfigurations, it is possible for elevations or the like, whichprotrude from one component in the direction of the other component, forexample, to be provided between the two components of themagnetorheological transmission apparatus.

Such a configuration is possible and preferred both in the case ofrotational mobility and in the case of linear mobility of the twocomponents with respect to one another.

Only one elevation can be provided or a plurality of elevations can beprovided. It is possible for a ball or a roller or another rotating bodyto be arranged on at least one elevation and to be at least partiallyaccommodated by the elevation.

If elevations are provided on one component, it is preferred for atleast one pole or at least one magnetization unit or at least one magnetor one coil to be provided on the other component. The number ofmagnetization units or poles can be 1 or else greater.

The shape of the elevations can fundamentally be arbitrary and can besemicircular, pointed or blunt, for example. The holding region ofrotating bodies is preferably accordingly rounded.

One or more magnetization units or poles can be in the form of anelectrical coil plus core or a permanent magnet or can consist ofremanence material or a combination thereof.

The distances between individual elevations and/or magnetization unitsare preferably approximately uniform, but can also be arbitrary.

The depth, i.e. the radial extent or the axial extent, of individualelevations or magnetization units with respect to others can bedifferent.

The field strength which is applied to or acts on the individualmagnetization units can, in particular, also vary at the same time.

The speed of the rotating bodies does not have to be equal to therolling speed, and can also deviate therefrom, for example by step-downor step-up transmissions. The inner part which is formed by theelevations, for example in the shape of a star, can be mountedoff-center to the outer part.

Such a magnetorheological transmission apparatus can be used, forexample, as a haptic knob with a latching pattern or in furniture anddrawer guides with positions.

The magnet or each magnetization unit or the inner part and/or the outerpart can also consist of remanence material.

Since magnetorheological fluids concatenate very rapidly upon theapplication of a magnetic field, it can be sufficient in the normalstate, for example when driving an automobile, if the magnetic field isturned off. It is generally entirely sufficient to only turn on thefield when a first rotational angle change is initiated. A significantamount of energy can thus be saved.

Alternatively, a base torque can be implemented with remanence. When arotational angle change is registered, a dynamic magnetic field can bebuilt up, which can also pulsate to generate a virtual latching pattern.

In configurations in which the remanence is utilized, the magnetic fieldfor the remagnetization can be externally applied. A corresponding coil,which acts through a cylinder, for example, can be used for theremagnetization.

The method according to the invention is used to operate technicalequipment and devices and, in particular, vehicles and particularlypreferably motor vehicles, a haptic operating device having a rotatingunit being used and selectable menu items being displayed on a displayunit, and a menu item being selected or chosen by rotating the rotatingunit. In particular, a torque profile is dynamically changed duringrotation of the rotating unit and/or the rotating unit latches at anumber of haptically perceptible latching points during rotation, thenumber of haptically perceptible latching points then being dynamicallychanged, in particular during operation.

The method according to the invention has many advantages since itenables simple and dynamically adapted operation. The individual menuitems can be selected by rotating the rotating unit and can be clearlyhaptically distinguished from one another since a latching point or astronger rotational resistance can be felt at each individual menu item.As a result of the dynamically changing number of haptically perceptiblelatching points during operation, the operation of the operating devicecan be optimally adapted to the respective requirements and to currentoperating states of the technical equipment or of the vehicle. Such adynamically adapted procedure is therefore not possible with the hapticoperating knobs from the prior art and is not known from the latter.

The latching points are preferably generated by deliberately generatinga magnetic field at a channel at least partially filled with amagnetorheological medium. Such a channel extends, in particular,between a basic body and a rotating unit which is rotated in order toactuate the haptic operating device.

An angular position of the rotating unit is preferably detected, and anintensity of the magnetic field is set on the basis of the detectedangular position. In this case, the angular position of the rotatingunit can be recorded in absolute or relative terms.

In preferred configurations, an end stop is dynamically generated in atleast one direction of rotation. The magnetic field is particularlypreferably set to be considerably stronger at the end stop than at alatching point. As a result of such a dynamically set end stop, an endstop can fundamentally be provided at any desired angle position, withthe result that the complete rotational angle does not need to be usedto arrive at an end stop. As a result, after relatively small rotationalangles, a user can also be easily made aware of the fact that yetfurther menu items are not provided during further rotation. An end stopcan thus be dynamically generated, for example, after 2, 3 or 4 latchingpoints.

A latching point is preferably generated at a determined angle positionby virtue of a stronger magnetic field being generated there or in thevicinity of the latching point than further away from the latchingpoint. For example, a stronger magnetic field can be generated atangular locations adjacent to the determined angle position than at theangle position determined for the latching point.

It is possible for the magnetic field to be intensified during arotational movement away from the latching point, with the result thatthe user can clearly feel the latching point.

It is possible and preferred for a relative local minimum of themagnetic field to be generated at a latching point, whereas relativemaxima of the magnetic field are generated in the immediate vicinity ofthe latching point. The magnetic field can be reduced again further awayfrom the latching point. This means that the magnetic field isintensified at a distance of up to 25% of the distance between twolatching points, for example, whereas it is set to be relatively smallat a latching point itself.

In preferred configurations, the angular distance between at least twoadjacent latching points is dynamically set. For example, the angulardistance between two latching points may be respectively 10 or 15° for anumber of 4, 6, 8 or 10 latching points, whereas the angular distancemay be increased to 30°, for example, in the case of only 2 latchingpoints. The relative angular distance can fundamentally be increased fora smaller number of latching points, whereas the angular distance isdecreased for a larger number of latching points.

However, it is also possible for an angular distance between twolatching points to be decreased—to a certain degree—if fewer latchingpoints are provided. For example, a relatively small angular distance of15° or the like can also be selected in the case of only 2 latchingpoints and therefore 2 menu items, whereas the angular distance may be30° if 4 menu items are selected or 4 corresponding latching points aredynamically generated. The latching pattern spacing may also always bethe same.

In all configurations, it is preferred for the rotating unit to beendlessly and/or freely rotatable in the switched-off state. However, itis also possible for only a certain rotational angle of 150°, 180°, 360°or 720° or the like to be possible if, for example, there is a directcable connection between a rotated part and a stationary part.

In all cases, it is also possible for a permanent magnet to ensure acertain base resistance during rotation in the switched-off state, forexample. It is also possible to provide a mechanical orpermanent-magnetic latching pattern for the switched-off state so thatthe user also receives haptic feedback in the switched-off state. In thecase of a mechanical latching pattern, it is conceivable for the latterto be electronically compensated for in the normal operating state, withthe result that, in the switched-off state, the user senses a mechanicallatching pattern which is completely dynamically superimposed orreplaced in the operating state.

In all configurations, it is preferred for the number of latching pointsto correspond to the number of currently available menu items. Thismeans that, after selection of a menu item and appropriate guidance to asubmenu, the number of then currently available latching pointscorresponds to the subitems in the then currently active submenu.

A selected menu item is preferably activated when the haptic operatingdevice and/or the rotating unit is/are pressed. In all configurations,it is also possible and preferred for a touch-sensitive screen or atouch-sensitive display unit (for example capacitive, inductive etc.) tobe used, in which a menu item can be selected by touching it with thefinger or the like, for example. In all of these configurations, it ispossible and preferred for both pressing of the haptic operating deviceand operation using the finger to be possible. This also applies tooperation using gesture control. A gesture control sensor can be usedadditionally or instead of the screen for this purpose.

The display unit may be an LCD, TFT, IPS, Retina, Nova, White Magic,OLED, AMOLED or other screen type.

An associated method step is preferably carried out and/or an associatedsubmenu is displayed and the number of latching points is dynamicallyadapted to the selectable menu items in the submenu when a menu item isactivated.

A further method is used for operation or control in or of self-drivingvehicles having an adaptive haptic operating device, the available menuitems and the latching points of the operating device being adapted onthe basis of an operating or driving state.

In this case, in particular, only those menu items or functions whichare permissible based on the operating or driving state (in particularself-driving or are driven) can be selected and executed. Menu itemsand/or functions which possibly result in danger or are confusing arepreferably hidden or deactivated.

Another method is used, in particular, for assisting with therehabilitation of persons after illnesses, a haptic operating devicebeing used. In this case, a variable rotational resistance is generated.In this case, the operating device can be used to open a door, turn aswitch etc. The latching pattern and the force can be adapted in aninfinitely variable manner.

In all variants, the haptic operating device has an infinite number ofpossible positions or latching patterns, in particular.

The combination of a touch display (display unit) plus a hapticoperating device (haptic knob) can be used in a wide variety ofapplications. The same basic configuration (hardware) can be “adapted”by means of different software. For example, the operating device can beused in the washing machine as a rotating controller with coarselatching patterns (delicates, low-temperature, prewash etc.), and can beused in a baking oven with an infinitely variable, but increasinglydifficult latching pattern for the purpose of adjusting the temperature.In all devices, the user therefore has a “known/identical” userinterface but nevertheless product-specific user interfaces. Themanufacturer hereby has more common parts, which makes everything morecost-effective.

Modern cameras have a large number of dials and operating knobs.Depending on the program selected, corresponding fine adjustments (forexample aperture stops etc. in this case) can be changed by means of thehaptic rotating unit (rotary knob) by pressing on the display (or aknob). Adapted latching patterns or latching points can be used foraperture stops and programs. A zoom can be operated in an infinitelyvariable manner with a central position at a focal length of 50 mm andwith stops at the end of the zoom. The actuation force may possibly beincreased shortly before the end stop.

These cameras may also be controlled using a mobile telephone or thelike. An operating device according to the invention is alsoadvantageous here.

The haptic operating device may also be the program selection element atone time and then the adjusting element for the zoom, each withdifferent latching patterns.

The haptic latching pattern may also be installed in the objective inthe multifunction rotating ring of the housing (multifunction ring inthe cameras). The latching pattern changes depending on the use of thering (zoom, aperture stops, shutter speed etc.).

In order to save space, weight and costs, the entire ring need not be inthe form of an MRF ring in this case, but rather may be controlled via asmall haptic element according to the present invention which is locatedto the side and is operatively connected via toothing or the like.

Persons with impaired eyesight can be assisted by corresponding feedbackfrom the haptic operating element, for example in the form of a Morsecode.

A room thermostat knob can indicate, for example, what temperature isbeing regulated. One pulse is one degree warmer, two short successivepulses are two degrees warmer. The temperature can be reduced if rotatedin the other direction. The same applies to ovens, baking ovens etc.

Braille is even virtually possible using the haptic operating device.The torque profile against the rotational angle (rotation of the hapticknob) results in a Morse code or braille.

Furthermore, the dialing of a number can be described as follows: digitsare equal to the number of haptic pulses.

Following a stroke or similarly severe illnesses/events, persons mustrelearn many functions. The opening of a door or door lock, the turningof a switch, for example of the washing machine, writing etc. must belearnt and trained again. An ideal tool for this is available with theadaptive haptic operating device. The latching pattern and the force orthe torque can be adapted in an infinitely variable manner and atraining program is therefore possible. This applies not only astrainers for the hand but also many more (joints, fingers, legs etc.).

The method according to the invention is particularly preferably carriedout using an apparatus according to the invention, thus resulting in aparticularly advantageous method of operation.

Not only data relevant to the situation can be displayed and adjusted onthe display unit, but other data, for example the time, SMS, thetelephone book, can also be displayed.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a haptic operating device and method, it is nevertheless not intendedto be limited to the details shown, since various modifications andstructural changes may be made therein without departing from the spiritof the invention and within the scope and range of equivalents of theclaims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows a cross section through a haptic operating device accordingto the invention;

FIG. 2 shows an enlarged detail from FIG. 1;

FIG. 3 shows a highly schematic view of the operating principle of amagnetorheological transmission apparatus of the haptic operating devicein cross section;

FIG. 4 shows another embodiment of a haptic operating device accordingto the invention;

FIG. 5 shows a slightly perspective illustration of the haptic operatingdevice according to FIG. 4;

FIG. 6 shows another embodiment of a haptic operating device accordingto the invention;

FIG. 7 shows another embodiment of a haptic operating device accordingto the invention;

FIGS. 8A-8L show a control sequence with a haptic operating deviceaccording to the invention;

FIGS. 9A-9C show possible torque profiles against the rotational angleof a haptic operating device according to the invention;

FIG. 10 shows another embodiment of a haptic operating device accordingto the invention; and

FIG. 11 shows an embodiment of a haptic operating device according tothe invention which can be moved or tilted.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of haptic operating devices 200 havingmagnetorheological transmission apparatuses 1 are explained below withreference to the accompanying figures, identical or similar parts beingprovided with the same reference symbols.

Referring now to the figures of the drawing in detail and first,particularly, to FIG. 1 thereof, there is shown a schematic crosssection of a first haptic operating device 200 according to theinvention, the haptic operating device 200 containing amagnetorheological transmission apparatus 1, the precise function ofwhich is explained further below with reference to FIG. 3.

FIG. 1 shows a cross section, the stationary basic body 201 being usedas the component 2 here, on which the rotating unit 202 is rotatablyheld as the component 3. The basic body 201 has a holding housing 211which is fastened to a separate base plate 210. For example, the holdinghousing 211 can be adhesively bonded to the base plate 210 after theparts arranged in the holding housing have been mounted. In comparisonwith the basic body 201, the rotating unit 202 is rotatably held here.The rotating unit 202 comprises a shaft 212 here, to which a holder 232is screwed via a screw 231. The holder 232 is used to hold andaccommodate the display unit 203 which is surrounded by the actualrotating unit 202. As a result, the rotating unit 202 can be externallygripped and rotated, whereas the display unit 203 remains substantiallycompletely visible on the top side of the haptic operating device evenif the user's hand rotates the rotary knob or the rotating unit 202.

The shaft 212 is rotatably mounted on the holding housing 211 via abearing 30. The bearing 30 may be in the form of a sliding bearing, forexample, but may also comprise any other rolling bearing.

An annular holding space 219, which is filled with an electrical coil 26as a field generation device 7 here, is provided in the internal space213 in the basic body 201, which is rotationally symmetrical here, andmore precisely in the holding housing 211. Possible clearances can befilled, for example, with a potting compound or a filler which issimultaneously used to hold the electrical coil 26 in the annularholding space 219.

As depicted on the left side of FIG. 1, it is possible for an additionalpermanent magnet 25 or a plurality of additional permanent magnets 25 tobe provided on the holding housing 211 in order to generate a permanentmagnetic field independently of a current source. If necessary, themagnetization of the permanent magnet 25 can be changed usingcorresponding magnetic pulses from the electrical coil 26.

A channel 5 which is partially filled with rotating bodies 11 asrotatable transmission elements or as magnetic field concentrators,which are cylindrical here and, in particular, are arrangedsymmetrically over the circumference of the channel 5, is provided inthe internal space 213 between the holding housing 211 and the shaft212. The rotating bodies co-rotate during rotation of the two components2, 3 with respect to one another since the rotating bodies 11 areusually in contact with the holding housing 211 and/or the shaft 212 andtherefore roll thereon.

At least one contact element 209 in the form of a contact ring 209(friction ring) can be provided for the purpose of assisting with therolling and ensuring rolling contact.

Such a contact ring may be in the form of an O-ring (round or angular orrectangular ring), in particular, and may consist of a rubber-likematerial, for example.

Such a contact ring 209 may be arranged, for example, in acircumferential groove 217 on the running surface 215 of the holdinghousing 211. It is also possible for a further contact ring 209 b to bearranged in a groove 216 on the running surface 214 on an enlargedcircumferential ring 218 of the shaft 212.

It is possible and preferred for a contact ring 209 to be arranged inthe groove 217 and for a contact ring 209 b to be arranged in the innercircumferential groove 216 on the running surface 214 of thecircumferential ring 218.

Alternatively, it is also possible for the individual rotatabletransmission elements or rotating bodies 11 as magnetic fieldconcentrators to each be provided with a contact ring 209 c, a contactring 209 c then extending around a rotating body 11. In the case of sucha configuration as well, it is ensured that the rotating bodies 11 andtheir contact ring 209 each have contact with the shaft 212 or theholding housing 211, thus ensuring continuous rotation of the rotatingbodies if the rotating unit 202 is rotated.

In the exemplary embodiment here, a defined axial distance between theholding housing 211 and an axial surface of the circumferential ring 218is ensured via a stop ring 233. The internal space 213 is sealed via aseal 46, with the result that the magnetorheological medium cannotescape from the internal space 213.

A circumferential gap, at which a sensor 206 which is used as an anglesensor is arranged, is provided between the cover or the holder for 232and the holding housing 211. The angle sensor 206 preferably consists ofat least two parts 207 and 208, the sensor part 207 having magnets orother positional marks or the like at particular angle positions, forexample, with the result that a rotational movement of the rotating unit202 can be detected at the holding housing 211 via the sensor part 208mounted on the electronics, for example. In this case, both an absoluteangle position and a relative angle change can be sensed. The anglesensor 206 or a separate actuation sensor 204 can be used to sense anaxial movement or an axial force on the rotating unit 202 or theoperating device 200 as a whole. For example, a slight distance changebetween the holder 232 and the holding housing 211, which can be sensedby the actuation sensor 204, can be achieved by exerting an axial force.It is also possible for certain parts or the outer rotating ring of therotating unit 202 to be axially displaceable counter to a spring force,with the result that axial actuation of the operating device 200 can besensed. The electronics of the haptic operating device preferablyoperate with a control clock of 4 kHz or more.

The display unit which is rotatable together with the rotating unit 202here can be supplied with the necessary data and the required electricalcurrent via a cable feed 241 and a central channel. An energy store 28can be internally or externally provided.

FIG. 2 shows an enlarged detail from FIG. 1, in which case the rotatingbody 11—the rotating bodies 11 of all of the embodiments may be referredto as rotatable transfer elements or as magnetic field concentrators—andthe electrical coil 26 and also a permanent magnet 25 are visible. Theaxial distance 223 between the end face 220 at the shaft 212 and the endface 221 at the holding housing 211 is clearly discernible here. Thisaxial distance 223 is considerably shorter than the radial distance 224between the circumferential ring 218 and the running surface 215 in theholding housing 211.

A short distance 223 is advantageous since the magnetic field 8 (compareFIG. 1) passes through the gap 222 in the axial direction. Relativelylow magnetic losses are possible with a thin gap.

The functional principle for generating torques in the haptic operatingdevice 200 is described below with reference to FIG. 3.

FIG. 3 shows a highly schematic cross-sectional view of amagnetorheological transmission apparatus 1 according to the inventionfor influencing the force transmission between two components 2 and 3.In this case, a rotating body 11 is provided as a separate part 4between the two components 2 and 3 in FIG. 1. The rotating body 11 is inthe form of a ball 14 here. However, it is likewise possible forrotating bodies 11 to be in the form of cylinders or ellipsoids, rollersor other rotatable rotating bodies. In the actual sense, rotating bodieswhich are not rotationally symmetrical, for example a gear wheel, orrotating bodies 11 having a particular surface structure can also beused as rotating bodies. The rotating bodies 11 are not used formounting relative to one another, but rather for transmitting torque.

A channel 5 which is filled here with a medium 6 is provided between thecomponents 2 and 3 of the magnetorheological transmission apparatus 1.The medium here is a magnetorheological fluid 20 which comprises, forexample, as the carrier fluid, an oil-containing ferromagnetic particle19. Glycol, fat, or viscous substances can also be used as the carriermedium without being restricted thereto. The carrier medium may also begaseous or it is possible to dispense with the carrier medium (vacuum).In this case, only particles which can be influenced by the magneticfield are filled into the channel.

The ferromagnetic particles 19 are preferably carbonyl iron powder, thesize distribution of the particles depending on the specific use. Aparticle size distribution of between one and ten micrometers isspecifically preferred, but larger particles of 20, 30, 40 and 50micrometers are also possible. Depending on the application, theparticle size can also become considerably larger and can even advanceinto the millimeter range (particle spheres). The particles may alsohave a special coating/casing (titanium coating, ceramic casing, carboncasing etc.) so that they better withstand the high pressure loads whichoccur depending on the application. For this application, the MRparticles can be produced not only from carbonyl iron powder (pure iron)but also from special iron (harder steel), for example.

The rotating body 11 is caused to rotate about its axis of rotation 12by the relative movement 17 of the two components 2 and 3 andpractically runs on the surface of the component 3. At the same time,the rotating body 11 runs on the surface of the other component 2, withthe result that there is a relative velocity 18 there.

Strictly speaking, the rotating body 11 does not have any direct contactwith the surface of the component 2 and/or 3 and therefore does not rolldirectly thereon. The free distance 9 between the rotating body 11 andone of the surfaces of the component 2 or 3 is 140 μm, for example. Inone specific configuration with particle sizes of between 1 μm and 10μm, the free distance is between 75 μm and 300 μm, in particular, andparticularly preferably between 100 μm and 200 μm.

The free distance 9 is, in particular, at least 10 times the diameter ofa typical mean particle diameter. The free distance 9 is preferably atleast 10 times the size of a largest typical particle. As a result ofthe lack of direct contact, a very low base friction/force/torque isproduced during relative movement of the components 2 and 3 with respectto one another.

If a magnetic field is applied to the magnetorheological transmissionapparatus 1, the field lines are formed on the basis of the distancebetween the rotating bodies 11 and the components 2, 3. The rotatingbody consists of a ferromagnetic material and of ST 37 here, forexample. The steel type ST 37 has a magnetic permeability μr ofapproximately 2000. The field lines pass through the rotating body andare concentrated in the rotating body. A high flux density prevails inthe channel 5 on the radial entry and exit surface of the field lines onthe rotating body. The inhomogeneous and strong field there results inlocal and strong cross-linking of the magnetically polarizable particles19. The effect is greatly increased by the rotational movement of therotating body 11 in the direction of the wedge forming in themagnetorheological fluid, and the possible braking or clutch torque isextremely increased far beyond the magnitude which can normally beproduced in the magnetorheological fluid. The rotating body 11 and thecomponent 2, 3 preferably at least partially consist of ferromagneticmaterial, which is why the magnetic flux density becomes higher, theshorter the distance between the rotating body 11 and the component 2,3. As a result, a substantially wedge-shaped region 16 forms in themedium, in which the gradient of the magnetic field increases greatlytoward the acute angle at the contact point/the region at the shortestdistance.

Despite the distance between the rotating body 11 and the component 2,3, the rotating body 11 can be caused to rotate by the relative velocityof the surfaces with respect to one another. The rotational movement ispossible without and also with an acting magnetic field 8.

If the magnetorheological transmission apparatus 1 is exposed to amagnetic field 8 from a magnetic field generation device 7 (notillustrated here in FIG. 1), the individual particles 19 of themagnetorheological fluid 20 are concatenated along the lines of themagnetic field 8. It should be noted that the vectors depicted in FIG. 1only roughly schematically illustrate that region of the field lineswhich is relevant to influencing the MRF 20. The field lines occursubstantially in a manner perpendicular to the surfaces of theferromagnetic components in the channel 5 and need not run in arectilinear manner, in particular in the acute-angled region 10.

At the same time, on the circumference of the rotating body 11, somematerial of the magnetorheological fluid 20 is concomitantly caused torotate, with the result that an acute-angled region 10 forms between thecomponent 3 and the rotating body 11. On the other side, an identicalacute-angled region 10 is produced between the rotating body 11 and thecomponent 2. The acute-angled regions 10 may have a wedge shape 16 inthe case of cylindrical rotating bodies 11, for example. The wedge shape16 impedes the further rotation of the rotating body 11, with the resultthat the effect of the magnetic field on the magnetorheological fluid isintensified since the acting magnetic field inside the acute-angledregion 10 results in greater cohesion of the medium 6 there. Thisintensifies the effect of the magnetorheological fluid in theaccumulated cluster (the chain formation in the fluid and therefore thecohesion or viscosity), which makes it difficult to rotate or move therotating body 11 further.

The wedge shape 16 makes it possible to transmit considerably greaterforces or torques than would be possible with a comparable structurewhich uses only the shear movement without a wedge effect.

The forces which can be directly transmitted by the applied magneticfield represent only a small portion of the forces which can betransmitted by the apparatus. The magnetic field makes it possible tocontrol the wedge formation and therefore the mechanical forceintensification. The mechanical intensification of themagnetorheological effect can be such that it is possible to transmit aforce, even after an applied magnetic field has been switched off, ifthe particles have been wedged.

It has been found that the wedge effect of the acute-angled regions 10results in a considerably greater effect of a magnetic field 8 of aparticular strength. In this case, the effect can be intensified by amultiple. In a specific case, the relative velocity of two components 2and 3 relative to one another was influenced approximately 10 times asmuch as in the prior art in the case of MRF clutches. The possibleintensification depends on different factors. It can possibly also beintensified by a greater surface roughness of the rotating bodies 11. Itis also possible for outwardly projecting projections to be provided onthe outer surface of the rotating bodies 11, which projections mayresult in even stronger wedge formation.

The wedge effect is distributed in a two-dimensional manner between therotating body 11 and the components 2 or 3.

FIG. 4 shows a schematic illustration of another embodiment of a hapticoperating device according to the invention in which the display unit203 is stationary and in which the rotating unit 202 arranged axiallybeside the display unit can be rotated without the display unit 203co-rotating. A magnetorheological transmission apparatus 1 is alsoprovided in the operating device 200 according to FIGS. 4 and 5 in orderto generate the required magnetic forces and the accordingly actingbraking forces or braking torques.

FIG. 6 shows a variant of the exemplary embodiment according to FIG. 4,in which case the cover with the display unit 203 is hinged, with theresult that, after opening, a fingerprint sensor 236 or the like(touchpad etc.) is available in order to authenticate a user, forexample.

FIG. 7 shows an operating device 1 according to the invention having anoperating knob 80 as a haptic operating device 200 and having a display81, from which the haptic operating device 200 projects upward. Thismeans both that the display 81 is suitable for representing informationhere and that the display unit 203 on the top side of the operatingdevice 200 is used to reproduce information and to select menu items.Buttons 83 can be actually or virtually provided on the touchscreen 82and can be actuated by pressing in order to initiate particular actions.In any case, it is possible to select menu items on the display unit 203by rotating the rotating unit 202 of the operating device 200.

The operating device 200 according to FIG. 7 has an operating knob or arotary knob 80 having a magnetorheological transmission apparatus 1. Thehousing as a component can be permanently fitted to a device, forexample. The shaft as a component is connected to the rotating part.Both components 2 and 3 are rotatably mounted with respect to oneanother via bearings. A thin gap as a free distance 9 is situatedbetween the rotating body 11 and the housing and also between therotating body 11 and the shaft. The space surrounding the rotatingbodies 11 and possibly virtually the entire internal space can be filledwith a magnetorheological fluid as the medium 6. A sealing ring 46 actsas a seal with respect to the bearing which is thus protected from theparticles in the magnetorheological fluid.

Activation of the coil 26 generates a magnetic field 8 which, as shownby the field lines depicted by way of example, passes through therotating bodies 11 and here otherwise substantially runs inside thehousing and the shaft. With an activated magnetic field of the coil 26,a corresponding resistance is produced in the medium 6 or the MR fluid,with the result that a corresponding resistance can be felt whenrotating the rotating part 85. Temporally pulsed or pulsating operation,as a result of which a pulsating resistance and therefore latching willbecome noticeable, is also possible, for example.

The respectively current angle position can be sensed via a rotaryencoder. As a result, arbitrary haptic signals can be output on thebasis of the control, depending on the position, rotational angle,angular velocity etc. The rotary encoder can also be supplemented with atorque sensor.

Two-dimensional haptic knobs or rotary knobs 80 can also be producedwith an additional MRF shear mode.

An MRF haptic knob can have a very small construction for actuatingdevices in SLR cameras and other cameras and in games consoles and otherhandheld computers. Such MRF coupling devices having a smallconstruction are highly suitable for cameras and other outdoorapplications on account of the small space requirement and the low powerconsumption in the range of milliwatts or below. The latching patterncan be set on the basis of the situation.

Three-dimensional movement elements with variable haptics and robust andprecise mounting are fundamentally difficult to produce and aretherefore not inexpensive. In contrast, the combination of anarrangement of the rotating bodies which is capable of pendulummovements with a magnetorheological fluid, for example, can be producedin a very cost-effective manner.

A four-dimensional rotary knob which can be displaced and can also beadditionally rotated in three directions, for example, can also beprovided.

The combination of a 3-D knob with longitudinal adjustment of an MRFwedge therefore results in a 4-D actuating element. A field generationunit can be used to influence or vary all four directions of movement.

It is also possible to use such haptic knobs on touch-sensitive displayssuch as touch displays in mobile telephones, PDAs, smartphones, portableand stationary computers and on screens, games consoles, tablet PCs,laptops etc. For this purpose, at least one haptic element in the formof a rotary knob, for example, is provided there.

Such a haptic element 200 can also be foldable/pivotable or displaceableand can be displaced, for example, from a position of rest on the edgeinto a position above the display. As soon as the haptic element isabove the display, the display on the display can change, that is to saya menu appears below or around the knob.

Instead of a kinematic and, for example, parallelogram-like pivotingmechanism, it is also possible to use an elastic/deformable elementwhich, as a flexible and semi-rigid arm, for example, can consist ofcoiled metal tubing in the form of a swan's neck. One advantage is thatthe user does not always have to grip the screen, which reduces soiling.In addition, the adjustment and the zooming, for example, take placemore quickly: gripping the screen with one finger and moving therotating controller with another finger can initiate a zooming process,for example. The same applies to the volume, writing with uppercase andlowercase letters or selecting special buttons or a second level duringtyping.

The user can thus also press with one finger on a separate menu bar inorder to search for the type of desired actuation. He then performs thedesired action using the rotating controller. The latching pattern ofthe rotating controller then adapts automatically, thus, for example,“on”—“off” or volume control with a latching pattern possibly having adynamic stop. If the screen is rotated during the actuation (touchdisplay) (for example, as in the case of mobile telephones or handheldcomputers—90° from portrait format to landscape format), the latchingpattern adapts automatically, i.e. it co-rotates. For example, if thesetting range were from 6 o'clock to 12 o'clock when it is held upright,this would change from 12 o'clock to 6 o'clock upon rotation by 90° inthe clockwise direction without adaptation. This also applies if thedisplay is installed in the knob itself. Such a haptic element can behaptic in all or individual directions (only rotate, rotate and press;joystick etc.). The haptics adjust themselves depending on the selectedaction.

One advantage can also result upon the selection of a list such as atelephone book list, for example, since such entries are often too smallfor “targeting” for large fingers.

Advantages also result in the dark or for people with spectacles who arenot currently wearing them. Feedback is received via the haptic rotatingcontroller and the user knows what he is doing when it is currentlydark, for example.

The functionality and the method of operation of an operating device 200according to the invention are explained below with reference to FIGS.8A to 8L using the example of the use in a motor vehicle.

In this case, FIG. 8A shows a plan view of the haptic operating device200 according to the invention of a motor vehicle. The haptic operatingdevice 200 may be used, in particular, to select an operating state ofthe motor vehicle. If a user sits in the motor vehicle and on thedriver's seat, for example, the haptic operating device 200 can directlydetect the presence of the driver and/or of the key or of anothersuitable identification object using a sensor (not illustrated) and canbe automatically changed from the switched-off state of rest to a moreactive state. In this state, the display unit 203 of the hapticoperating device 200 displays the operating state of the motor vehicle,for example.

FIG. 8A illustrates the operating state “off”. The display unit 203centrally displays a graphical symbol 205 with the operating state onthe rotating unit 202. A menu ring 235, on which the individualselectable menu items 225 are depicted, is graphically illustratedfurther on the outside. There are three menu items in FIG. 8a , in whichcase the indicator 234 is illustrated beside the selected operatingstate or beside the currently active operating state.

Rotating the rotating unit 202 in the direction of rotation 227 (here tothe right or in the clockwise direction) then makes it possible toselect the menu item for setting the radio or the audio system. Thisstate is illustrated in FIG. 8B where the clef is depicted as thegraphical symbol 205 in the center of the display unit 203. Theindicator 234 indicates that the corresponding menu item 225 is active.

Rotating the rotating unit 202 further finally makes it possible toactivate the starting function of the motor vehicle, as shown in FIG.8C. The engine can be started by pressing the touch-sensitive surface ofthe display unit 203.

After the engine has been started by actuating the touch-sensitivebutton of the display unit 203 and/or by axially pressing the rotatingunit 202 or the entire operating device 200, the engine is started, thusresulting in the state for an automatic vehicle, which is illustrated inFIG. 8D. In this case, the parking function is activated, with theresult that the vehicle is not unintentionally caused to move.Irrespective of how the automobile was parked, the parking function isactivated in any case after restarting, with the result that reliableprevention of unintentional driving is ensured.

This is very advantageous since no mechanical resetting is required forthis. Although the haptic operating device 200 detects the angleposition of the rotating unit 202, this is only necessary and usefulduring operation. After the vehicle has been restarted, all settings arereset to the basic settings, with the result that the state “P” alwaysresults after the engine has been restarted irrespective of the angleposition of the rotating unit and the state in which the vehicle isstopped and the engine is switched off.

Actuating the rotating unit 202 and rotating it in the clockwisedirection results in the reverse gear being reached as the next latchingpoint, as illustrated in FIG. 8E. Rotation into the position “N” can beblocked in this case (very high braking torque) if the foot brake orparking brake is not actuated at the same time, for example. Furtherrotation changes the rotating unit to the menu item “N” (idling), asshown in FIG. 8F.

The next latching point corresponds to the menu item “D”, as shown inFIG. 8G. Actuating the rotating unit 202 in the axial direction orpressing the touch-sensitive display activates the operating mode “D”and the driver can drive away.

If, in contrast, the menu item “S” is actuated, a submenu is activatedand the selection possibilities from eight different gears here areprovided, as illustrated in FIG. 8H. Appropriate rotation of therotating unit 202 can activate one of the eight gears by means of thecorresponding menu item S1 to S8. In this case, each gear may beassigned an arbitrary latching pattern/torque profile, for example, withthe result that the operator recognizes the selected position withoutlooking.

A rotational movement in the opposite direction, that is to say in theanticlockwise direction, leads back to the other menu items.

In all cases, the number of latching points for the rotating unit 202 isadapted to the number of available menu items. This means that eightdifferent latching points are provided in FIG. 8H, whereas six differentmenu items can be illustrated and selected in FIG. 8K, for which sixlatching points are accordingly provided. Right-hand and left-hand endstops are dynamically generated here, with the result that the rotatingunit cannot be rotated further as desired in the switched-on state.

If the rotating unit 202 is rotated back to the starting point, asillustrated in FIG. 8L, the symbol for stopping the engine isdynamically displayed. The engine is stopped by pressing the symbol orby actuating the rotating unit 202 or the operating device 200 and thestate from FIG. 8A is reached again.

The starting or stopping knob need not necessarily be on the displayunit, but rather may also be an independent knob, for example in thevehicle console.

Overall, a haptic rotary knob is provided, the haptic latching patternof which is oriented on the basis of the available menu items in a menu.The available latching points are generated dynamically or adaptively.

FIGS. 9A, 9B and 9C illustrate possible embodiment variants for thedynamically generated magnetic field or the dynamically generatedbraking torque on the basis of the rotational angle.

In this case, FIG. 9A shows a variant in which a left-hand end stop 228and a right-hand end stop 229 are generated. During further rotation, ahigh magnetic field or stop torque 238 is generated there, as a resultof which the rotating unit 202 opposes a high resistance to a rotationalmovement.

A first latching point 226 corresponding to a first menu item 225 isprovided directly beside the left-hand end stop 228. If the next menuitem is intended to be selected, the rotating unit 202 must be rotatedin the clockwise direction. For this purpose, the dynamically generatedhigher magnetic field or latching torque 239 or its frictional torquemust be overcome before the next latching point 226 is reached. In FIG.9A, a constant magnetic field is respectively generated at the latchingpoints 226 and in the regions in between for a certain angular range,which magnetic field is considerably lower at the latching points thanin the regions in between and is again considerably lower than at thestops 228, 229.

An angular distance 237 between individual latching points can bedynamically changed and is adapted to the number of available latchingpoints or menu items.

FIG. 9B shows a variant in which the magnetic field does not suddenlyincrease toward the end stops 228, 229 but rather has a steep profile.Furthermore, ramp-like gradients of the magnetic field are respectivelyprovided at the latching points 226 toward both rotation sides, as aresult of which the rotational resistance increases in the correspondingdirections of rotation. Only three latching points 226 are provided herewith the same operating device 200, the angular distance 237 of whichlatching points is greater than in the example according to FIG. 9A.

FIG. 9C shows a variant in which there is a lower rotational resistancebetween individual latching points 226 and an increased magnetic field239 is respectively generated only directly adjacent to the latchingpoints 226 in order to enable engagement at the individual latchingpoints 226 and, at the same time, to provide only a low rotationalresistance between individual latching points.

In principle, it is also possible to mix the methods of operation andthe magnetic field profiles shown in FIGS. 9A, 9B and 9C. For example,the magnetic field profile can accordingly be set differently fordifferent submenus.

If the rotating unit is not rotated, that is to say the angle isconstant, the current is preferably continuously reduced over time. Thecurrent can also be varied on the basis of the velocity (rotationalangle velocity of the rotating unit).

FIG. 10 shows another embodiment variant of the haptic operating device200 having a stationary display unit 203. The watch plate 250 isarranged beneath the display unit 203. The outer part 249 having therotating unit 202, which is in the form of an aluminum knob in thiscase, is rotatably held on the shaft 212. The rotating bodies 11 areagain in a channel 5 and act as magnetic field concentrators. The coil26 is used to generate a magnetic field. The O-ring 245 providessealing. A spacer sleeve 246 is used to set the distance. The lock nut247 is used to secure the shaft 212. The lock nut 247 is covered by thehousing base toward the bottom.

FIG. 11 shows an exemplary embodiment in which the operating device 200can be moved in at least one dimension. It may thus be formed on aninfotainment system of a motor vehicle, for example. The operating knobcan be horizontally (and/or) vertically movable, as indicated by thearrows in FIG. 11. It is also possible for the operating knob to betiltable (and possibly not movable). Tilting can also be carried out intwo or more directions. A suitable menu item can be selected by means ofmoving (tilting). If the operating knob is moved laterally, for example,the next menu item in each case can be selected and can be displayed onthe display 81 and/or 203. In this configuration, it is possible todispense with the display 203. Even faster selection is enabled as aresult. Like the rotation of the haptic knob, the movement can also behaptically highlighted (for example a short stop at the menu items).When using a touchscreen or a similarly touch-sensitive display and anoperating element which moves across the latter, the touchscreen itselfcan be used to detect the position. The operating knob transmits theposition to the display, for example during movement, as is carried outby a finger, for example in the case of a “slider” (unlocking of amobile phone). However, the movement position can also be detected usingposition elements according to the prior art (length measuring systems,image recognition etc.).

This also applies to an (axial) pressing function (for example forconfirming a selected choice). The touchscreen can be used in this casetoo, the operating knob which moves across it virtually being the “humanfinger”.

This movability is also advantageous when a change is made betweenself-driving and autonomous driving in an automobile, for example.During self-driving, the haptic operating element is used as a gearselection lever; this function is no longer required during autonomousdriving and the operating element can be used for other functions. Theoperating element can then remain at the same position and can undertakethe new functions. However, this is possibly confusing for the user andit is better if the knob has a different function only after having beenmoved to a different position. The function of the operating element canthus also be assigned and used again without looking. The practice ofmoving the operating element is more cost-effective and morespace-saving in this case than implementing two haptic knobs (one ofwhich is mostly always unused).

Overall, the invention provides an advantageous haptic operating device200 and an accordingly advantageous method for controlling a motorvehicle or else domestic appliances, for example, in which case adisplay unit on which the selectable menu items are displayed iscentrally provided on the haptic operating knob. The number and type oflatching points are dynamically adapted to the number of available menuitems.

In all cases, the effective torque can be set on the basis of the speedusing pulse width modulation (PWM), for example. Large axial and radialforces can be generated using an oblique expanding mandrel. Theparticles may have a round, rod-shaped or any other form.

The rheological fluid may consist of a wide variety of constituentswhich individually or in combination may be: Fe, carbon steel, NdFeB(neodymium), AINiCo, samarium, cobalt, silicon, carbon fiber, stainlesssteel, polymers, soda-lime glass, ceramic and non-magnetic metals andthe like. Dimorphic magnetorheological fluids containing nanotubesor/and nano wires are also possible.

The carrier fluid may consist, in particular, of the followingconstituents or a combination thereof: oils and preferably synthetic ornon-synthetic oils, hydraulic oil, glycol, water, fats and the like.

The device according to the invention and as illustrated, for instance,in FIG. 1 was constructed several times. It exhibited a measured basetorque of approx. 0.015 Nm and a maximum torque of greater than 5 Nm.That is, a factor of well over 300 has been shown to be available withthe invention.

The sensor system, for example the sensor 206, has a high detectionresolution. This makes it possible to detect certain movement patternswith great accuracy. If, by way of example, the user moves the rotatingcomponent according to a given pattern (e.g., quick trembleback-and-fro, or repeated left/right turn), the control unit triggers anew operation, such as selecting a given submenu or asuperordinate-level menu. By way of example, when the actuator iscurrently used to scan available radio stations, the user may select acurrently displayed station by a quick “wiggle” of the actuator (e.g.,three times left, three times right). Due to the high resolution of thesensors, only very slight movements for the detection pattern aresufficient for the control system to “know” with great certainty theuser's input.

The following is a summary list of reference numerals and thecorresponding structure used in the above description of the invention:

1 Transmission apparatus, equipment

2, 3 Component

4 Separate part

5 Channel

6 Medium

7 Magnetic field generation device

8 Field

9 Free distance

10 Acute-angled region

11 Rotating body

12 Axis of rotation

13 Rotating body

14 Ball

15 Cylinder

16 Wedge shape

17 Direction of the relative movement

18 Direction of the relative movement

19 Magnetic particle

20 Fluid

25 Permanent magnet

26 Coil

27 Control device

28 Energy store

30 Bearing

46 Sealing ring

80 Operating knob

81 Display

82 Touchscreen

83 Button

200 Operating device

201 Basic body

202 Rotating unit

203 Display unit

204 Actuation sensor

205 Graphical symbol

206 Angle sensor

207 Sensor part

208 Sensor part, electronics

209 Contact ring, friction ring

210 Base plate

211 Holding housing

212 Shaft

213 Internal space

214 Running surface of 212

215 Running surface of 211

216 Groove

217 Groove

218 Circumferential ring with 214 and 216

219 Holding space for 26

220 End face of 218

221 End face of 211

222 Gap

223 Axial distance

224 Radial distance

225 Menu item

226 Latching point

227 Direction of rotation

228 End stop

229 End stop

230 Cover

231 Screw

232 Holder

233 Stop ring

234 Indicator

235 Menu ring

236 Fingerprint sensor

237 Angular distance

238 Stop torque

239 Latching torque

240 Base torque

241 Cable

242 Outer limb

243 Radially inner region

244 Inner limb

245 O-ring

246 Distancing sleeve

247 Counter nut

248 Housing floor, base

249 Outer part

250 Watch plate

1. A haptic operating device (200) having a basic body (201) and arotating unit (202) and a magnetorheological transmission apparatus (1)with at least two components (2, 3) which can be coupled and thecoupling intensity of which can be influenced, a magnetorheologicalmedium (6) which can be influenced by a magnetic field (8) and hasmagnetically polarizable particles (19) being arranged in a channel (5)between the couplable components (2, 3) for the purpose of influencingthe coupling intensity, and at least one magnetic field generationdevice (7) for generating at least one magnetic field (8) being providedin order to influence the magnetorheological medium (6) using themagnetic field (8), the basic body (201) being coupled to one of the twocomponents (2, 3) and the rotating unit (202) being coupled to the otherof the two components (3, 2), at least one rotatable transmissionelement being arranged in the channel (5) as a magnetic fieldconcentrator, the rotatable transmission element being caused to rotateduring a rotational movement of at least one of the components (2, 3)which can be coupled.
 2. The haptic operating device (200) as claimed inclaim 1, the basic body (201) comprising a base plate (210) and anannular holding housing (211) with a holding space (219) arranged in thelatter, the holding space (219) being radially delimited to the outsideby an outer limb (242) of the holding housing (211) extendingsubstantially in the axial direction, and a shaft (212) which isconnected to the rotating unit (202) in a rotationally fixed mannerbeing rotatably held centrally on the holding housing (211), and anelectrical coil (26) being held in the holding space (219), and acircumferential ring (218) which is connected to the shaft (212) in arotationally fixed manner adjoining the holding housing (211) in aradially inner region (243) in a manner separated by a thin axial gap(222), and the channel (5) being arranged in the holding space (219) andbeing radially delimited to the outside by the outer limb (242) andbeing radially delimited to the inside substantially by thecircumferential ring (218), with the result that a substantial part ofthe magnetic field from the magnetic field generation device (7) runsthrough the holding housing, the channel (5) and the circumferentialring (218).
 3. The haptic operating device (200) as claimed in claim 2,the holding housing (211) comprising an inner limb (244) in the radiallyinner region (243), which inner limb is adjoined by the circumferentialring (218) in a manner separated by the thin axial gap (222).
 4. Thehaptic operating device (200) as claimed in claim 3, a radial crosssection of the holding housing (211) having an approximately U-shapedconfiguration and encompassing the holding space (219) between the innerlimb and the outer limb, the outer limb (242) being longer than theinner limb (244).
 5. The haptic operating device (200) as claimed inclaim 3 or 4, the shaft (212) being held in a central passage on theinner limb (244), and the electrical coil (26) being held in the holdingspace (219) between the inner and outer limbs.
 6. The haptic operatingdevice (200) as claimed in one of the three preceding claims, the innerlimb being separated from the circumferential ring (218) connected tothe shaft (212) by the thin axial gap (222).
 7. The haptic operatingdevice (200) as claimed in one of the preceding claims, thecircumferential ring (218) being made from a soft magnetic material andthe shaft (212) having a hardened surface or surface coating.
 8. Thehaptic operating device (200) as claimed in one of the preceding claims,a display unit (203) being assigned.
 9. The haptic operating device(200) as claimed in the preceding claim, the rotating unit (202)surrounding the display unit (203) at least in sections.
 10. The hapticoperating device (200) as claimed in one of the preceding claims, anactuation sensor (204) for sensing an axial actuation travel beingarranged on the basic body (201) and/or the rotating unit (202).
 11. Thehaptic operating device (200) as claimed in at least one of the twopreceding claims, the display unit (203) being connected to the basicbody (201) in a rotationally fixed manner, and the rotating unit (202)being rotatable with respect to the display unit (203), or the displayunit (203) being connected to the rotating unit (202) in a rotationallyfixed manner and being rotatable, together with the rotating unit (202),with respect to the basic body (201).
 12. The haptic operating device(200) as claimed in at least one of the preceding claims, a sensor (206)being provided, which sensor can be used to sense an angle change and/oran absolute angle position between the rotating unit (202) and the basicbody (201).
 13. The haptic operating device (200) as claimed in at leastone of the preceding claims, a control device (27) being provided, whichcontrol device is designed to accordingly rotate a representation ofcontents of the display unit (203) in the opposite direction on thebasis of a signal from the sensor (206).
 14. The haptic operating device(200) as claimed in at least one of the preceding claims, at least oneseparate contact element (209) being arranged between the two components(2, 3).
 15. The haptic operating device (200) as claimed in thepreceding claim, the contact element (209) being elastic.
 16. The hapticoperating device (200) as claimed in at least one of the precedingclaims, at least a plurality of rotatable transmission elements in theform of rotating bodies (11) being provided in the channel (5).
 17. Thehaptic operating device (200) as claimed in at least one of the twopreceding claims, the shaft (212) being rotatably supported at one endon the base plate (210).
 18. The haptic operating device (200) asclaimed in at least one of the three preceding claims, the basic body(201) and the shaft (212) each having a circumferential running surface(214, 215) for the rotatable transmission elements (11) adjacent to thebase plate (210).
 19. The haptic operating device (200) as claimed inthe preceding claim, at least one running surface (214, 215) having atleast one circumferential groove (216, 217) for the rotatabletransmission elements (11).
 20. The haptic operating device (200) asclaimed in the preceding claim, the running surface (214) of the shaft(212) being formed on the circumferential ring (218) with an increaseddiameter.
 21. The haptic operating device (200) as claimed in at leastone of the preceding claims, the electrical coil (26) being arrangedsubstantially axially adjacent to the rotatable transmission elements(11) and the rotatable transmission elements being arranged axiallybetween the electrical coil (26) and the base plate.
 22. The hapticoperating device (200) as claimed in at least one of the precedingclaims, the holding housing (211) and the circumferential ring (218)consisting of a material with better magnetic conductivity than the baseplate (210).
 23. The haptic operating device (200) as claimed in atleast one of the preceding claims, the actuation sensor (204) sensing adistance between the basic body (201) and the rotating unit (202). 24.The haptic operating device (200) as claimed in at least one of thepreceding claims, a free distance (9) between the rotatable transmissionelement and the component (2, 3) being at least twice as large as atypical average diameter of the magnetically polarizable particles (19)in the magnetorheological medium (6), and at least one region (10)containing the magnetorheological medium (6) being provided between therotatable transmission element (11) and at least one component (2, 3),the magnetic field (8) from the magnetic field generation device (7)being able to be applied to said region in order to selectivelyconcatenate the particles (19) and/or wedge them with the rotating body(11) or release them.
 25. The haptic operating device (200) as claimedin the preceding claim, the acute-angled region (10) between therotatable transmission element (11) and one component (2, 3) tapering inthe direction of the relative movement (17, 18) of the component (2, 3)relative to the rotatable transmission element (11).
 26. A method foroperating technical equipment, devices and, in particular, vehicles, ahaptic operating device (200) having a rotating unit (202) being usedand selectable menu items (225) being displayed on a display unit (203),and a menu item (225) being selected by rotating the rotating unit(202), and the rotating unit (202) latching at a number of hapticallyperceptible latching points (226) during rotation, characterized in thatthe number of haptically perceptible latching points (226) isdynamically changed.
 27. The method as claimed in the preceding claim,the torque profile being dynamically changed during rotation of therotating unit.
 28. The method as claimed in one of the two precedingclaims, the latching points (226) being generated by deliberatelygenerating a magnetic field (8) at a channel (5) at least partiallyfilled with a magnetorheological medium (6).
 29. The method as claimedin one of the three preceding claims, an angular position (227) of therotating unit (202) being detected, and an intensity of the magneticfield (8) being set on the basis of the detected angular position (227).30. The method as claimed in one of the four preceding claims, an endstop (228, 229) being dynamically generated in at least one direction ofrotation (227), the magnetic field (8) being set to be considerablystronger at the end stop (228, 229) than at a latching point (226). 31.The method as claimed in one of the five preceding claims, a latchingpoint (226) being generated at a determined angle position by virtue ofa stronger magnetic field being generated at angular locations adjacentto the determined angle position than at the angle position determinedfor the latching point (226).
 32. The method as claimed in one of thesix preceding claims, an angular distance (237) between at least twoadjacent latching points being dynamically set.
 33. The method asclaimed in one of the seven preceding claims, the rotating unit (202)being endlessly and/or freely rotatable in the switched-off state. 34.The method as claimed in one of the preceding claims, the rotating unit(202) being locked in the switched-off state and being unlocked when therotating unit (202) is gripped at the beginning of a rotationalmovement.
 35. The method as claimed in one of the preceding claims, therotating unit (202) being unlocked in the switched-off state and beinglocked when the rotating unit (202) is gripped at the beginning of arotational movement.
 36. The method as claimed in one of the tenpreceding claims, at least one permanent magnet (25) being used, themagnetic field of which can have a magnetic field of an electrical coil(26) dynamically superimposed on it.
 37. The method as claimed in one ofthe eleven preceding claims, the number of latching points correspondingto the number of currently available menu items.
 38. The method asclaimed in one of the twelve preceding claims, a selected menu itembeing activated when the haptic operating device (200) and/or therotating unit (202) is/are pressed and in particular an associatedmethod step being carried out or an associated submenu being displayedand the number of latching points being dynamically adapted to theselectable menu items in the submenu when a menu item is activated. 39.The method, in particular as claimed in one of the thirteen precedingclaims, for operation or control in or of self-driving vehicles havingan adaptive haptic operating device (200), characterized in that theavailable menu items and the latching points of the operating device(200) are adapted on the basis of an operating or driving state.
 40. Themethod as claimed in the preceding claim, characterized in that onlythose menu items which are permissible and/or do not result in anydanger based on the operating or driving state can be selected andexecuted.
 41. A method for assisting, in particular, with therehabilitation of persons after illnesses, a haptic operating device(200) being used, characterized in that a variable rotational resistanceis generated.